Collected Evidence: Collected Evidence: Cease or prohibit aggregate extraction Seven studies examined the effects of ceasing or prohibiting aggregate extraction on subtidal benthic invertebrate populations. One study was in the English Channel (France), one in the Mediterranean Sea (Italy), one a global study, and four in the North Sea (UK, Belgium).   COMMUNITY RESPONSE (6 STUDIES) Overall community composition (4 studies): One global systematic review found that it took nine months to several decades for overall invertebrate community composition to recover after ceasing aggregate extraction. One before-and-after, site comparison study in the Mediterranean Sea and one of two site comparison studies in the North Sea found that after ceasing aggregate extraction overall invertebrate community composition became more similar to pre-extraction and/or natural site communities. Overall richness/diversity (5 studies): Two before-and-after, site comparison studies in the English Channel and the Mediterranean Sea and one of two site comparison studies in the North Sea found that after ceasing aggregate extraction, overall invertebrate species richness and/or diversity became more similar to that of pre-extraction and/or natural sites. The other site comparison found that species richness did not change over time and remained different to that of natural sites. One replicated, site comparison study in the North Sea found that 21 months after ceasing aggregate extractiom, invertebrate species richness was similar to that of natural sites. Worm community composition (1 study): One before-and-after study in the North Sea found that after ceasing aggregate extraction, nematode worm community composition remained different to the pre-extraction community. Worm richness/diversity (1 study): One before-and-after study in the North Sea found that after ceasing aggregate extraction, nematode worm species richness remained different to pre-extraction richness. POPULATION RESPONSE (6 STUDIES) Overall abundance (5 studies): Two before-and-after, site comparison studies in the English Channel and the Mediterranean Sea and one of two site comparison studies in the North Sea found that after ceasing aggregate extraction overall invertebrate abundance and/or biomass became more similar to that of pre-extraction and/or natural sites. The other site comparison found that abundance and biomass did not change over time and remained different to that of natural sites. One replicated, site comparison study in the North Sea found that 21 months after ceasing aggregate extraction, invertebrate abundance was similar to that of natural sites. Worm abundance (1 study): One before-and-after study in the North Sea found that after ceasing aggregate extraction, nematode worm abundance remained different to pre-extraction abundance. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2070https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2070Mon, 21 Oct 2019 14:07:13 +0100Collected Evidence: Collected Evidence: Cease or prohibit shipping  Three studies examined the effects of ceasing or prohibiting shipping on subtidal benthic invertebrate populations. All studies were in the North Sea (Belgium, Germany, Netherlands).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One site comparison study in the North Sea found that areas closed to shipping developed different overall invertebrate community compositions compared to areas where shipping occurred. Overall species richness/diversity (1 study): One site comparison study in the North Sea found that areas closed to shipping did not develop different overall invertebrate species richness and diversity compared to areas where shipping occurred. POPULATION RESPONSE (2 STUDIES) Overall abundance (2 studies): Two site comparison studies (one before-and-after) in the North Sea found that areas closed to shipping had similar overall invertebrate abundance and biomass compared to areas where shipping occurred. Overall abundance (2 studies): Two site comparison studies (one before-and-after) in the North Sea found that areas closed to shipping had similar overall invertebrate abundance and biomass compared to areas where shipping occurred. OTHER (2 STUDIES) Overall community energy flow (1 study): One before-after, site comparison study in the North Sea found that after closing an area to shipping, invertebrate community energy flow did not change, but it increased in nearby areas where shipping occurred. Species energy flow (1 study): One before-and-after, site comparison study in the North Sea found that closing an area to shipping had mixed effects on species-level energy flow.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2086https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2086Mon, 21 Oct 2019 14:54:50 +0100Collected Evidence: Collected Evidence: Cease or prohibit all types of fishing Five studies examined the effects of ceasing or prohibiting all types of fishing on subtidal benthic invertebrate populations. All studies were in the North Sea (Belgium, Germany, Netherlands, UK).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (2 studies): Two site comparison studies (one before-and-after) in the North Sea found that areas closed to all fishing developed different overall invertebrate community compositions compared to fished areas. Overall species richness/diversity (2 studies): One of two site comparison studies (one before-and-after) in the North Sea found that areas closed to all fishing did not develop different overall invertebrate species richness and diversity compared to fished areas after three years, but the other found higher species richness in the closed areas after 20 years. POPULATION RESPONSE (3 STUDIES) Overall abundance (2 studies): Two site comparison studies (one before-and-after) in the North Sea found that areas closed to all fishing had similar overall invertebrate abundance and biomass compared to fished areas after three and five years. Crustacean abundance (1 study): One before-and-after, site comparison study in the North Sea found that closing a site to all fishing led to similar numbers of lobster compared to a fished site after 20 months. Crustacean condition (1 study): One before-and-after, site comparison study in the North Sea found that closing a site to all fishing led to larger sizes of lobster compared to a fished site after 20 months. OTHER (1 STUDY) Overall community energy flow (1 study): One before-after, site comparison study in the North Sea found that, during the 12–14 months after closing an area to all fishing, the invertebrate community structure (measured as energy flow) at sites within the closed area did not change, but that it increased in nearby fished sites. Species energy flow (1 study): One before-and-after, site comparison study in the North Sea found that closing an area to all fishing for 12–14 months had mixed effects on species-level energy flow. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2096https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2096Mon, 21 Oct 2019 15:32:10 +0100Collected Evidence: Collected Evidence: Cease or prohibit commercial fishing Three studies examined the effects of ceasing or prohibiting commercial fishing on subtidal benthic invertebrate populations. Two studies were in the Tasman Sea (New Zealand), the third on Gorges Bank in the North Atlantic Ocean (USA).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One site comparison study in the Tasman Sea  found that an area closed to commercial trawling and dredging for 28 years had different overall invertebrate communities than an area subject to commercial fishing. Overall species richness/diversity (1 study): One site comparison study on Georges Bank found no difference in invertebrate species richness between an area closed to commercial fishing for 10 to 14 years and a fished area. POPULATION RESPONSE (3 STUDIES) Overall abundance (2 studies): Two site comparison studies in the Tasman Sea  and on Georges Bank found that areas prohibiting commercial fishing for 10 to 14 years and 28 years had greater overall invertebrate abundance compared to areas where commercial fishing occurred. One of the studies  also found higher biomass, while the other found similar biomass in closed and fished areas. Crustacean abundance (1 study): One replicated, site comparison study in the Tasman Sea found that in commercial fishing exclusion zones lobster abundance was not different to adjacent fished areas after up to two years. OTHER (1 STUDY) Overall community biological production (1 study): One site comparison study in the Tasman Sea  found that an area closed to commercial trawling and dredging for 28 years had greater biological production from invertebrates than an area where commercial fishing occurred. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2097https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2097Mon, 21 Oct 2019 15:41:48 +0100Collected Evidence: Collected Evidence: Establish temporary fisheries closures Six studies examined the effects of establishing temporary fisheries closures on subtidal benthic invertebrates. One study was in the English Channel (UK), one in the D’Entrecasteaux Channel (Australia), one in the North Pacific Ocean (USA), two in the Mozambique Channel (Madagascar), and one in the North Sea (UK).   COMMUNITY RESPONSE (2 STUDIES) Overall species richness/diversity (1 study): One replicated, site comparison study in the English Channel found that sites seasonally closed to towed-gear fishing did not have greater invertebrate species richness than sites where towed-fishing occurred year-round. Mollusc community composition (1 study): One replicated, before-and after study in the D’Entrecasteaux Channel found that temporarily reopening an area previously closed to all fishing for 12 years only to recreational fishing led to changes in scallop species community composition over four fishing seasons. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, site comparison study in the English Channel found that sites seasonally closed to towed-gear fishing did not have a greater invertebrate biomass than sites where towed-fishing occurred year-round. Crustacean abundance (1 study): One before-and-after, site comparison study in the North Sea found that reopening a site to fishing following a temporary 20-month closure led to lower total abundance but similar marketable abundance of European lobsters compared to a continuously-fished site after a month. Mollusc abundance (5 studies): One replicated, site comparison study English Channel found that sites seasonally closed to towed gear did not have higher abundance of great scallops than sites where towed-fishing occurred year-round. Two before-and after, site comparison studies (one replicated) in the Mozambique Channel found that temporarily closing an area to reef octopus fishing did not increase octopus abundance/biomass compared to before closure and to continuously fished areas. Two replicated, before-and after studies in the D’Entrecasteaux Channel and the North Pacific Ocean found that temporarily reopening an area previously closed to all fishing to recreational fishing only led to a decline in scallop abundance after four fishing seasons and in red abalone after three years. Mollusc condition (3 studies): One replicated, before-and after study in the North Pacific Ocean found that temporarily reopening an area previously closed to fishing led to a decline in the size of red abalone after three years. Two before-and after, site comparison studies (one replicated) in the Mozambique Channel found that temporarily closing an area to reef octopus fishing increased the weight of octopus compared to before closure and to continuously fished areas, but one also found that this effect did not last once fishing resumed. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2098https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2098Tue, 22 Oct 2019 08:34:46 +0100Collected Evidence: Collected Evidence: Cease or prohibit bottom trawling Four studies examined the effects of ceasing or prohibiting bottom trawling on subtidal benthic invertebrate populations. Two studies were in the Bering Sea (USA), one in the North Sea, and one in the Mediterranean Sea (Italy).   COMMUNITY RESPONSE (3 STUDIES) Overall community composition (2 studies): Two site comparison studies (one before-and-after, one replicated) in the North Sea and the Mediterranean Sea found that in areas prohibiting trawling for either 15 or 20 years, overall invertebrate community composition was different to that of trawled areas. Overall species richness/diversity (3 studies): Two of three site comparison studies (one paired, one before-and-after, one replicated) in the Bering Sea, the North Sea, and the Mediterranean Sea found that invertebrate diversity was higher in sites closed to trawling compared to trawled sites after either 37 or 15 years, but the other found no differences after 20 years. POPULATION RESPONSE (3 STUDIES) Overall abundance (2 studies): One of two site comparison studies (one paired, one replicated) in the Bering Sea and the Mediterranean Sea found that total invertebrate abundance was higher in sites closed to trawling compared to trawled sites after 37 years, but the other found no differences after 20 years. Both found no differences in total invertebrate biomass. Unwanted catch overall abundance (1 study): One replicated, before-and-after, site comparison study in the Bering Sea found that during the three years after closing areas to all bottom trawling, unwanted catch of crabs appeared to have decreased, while no changes appeared to have occurred in nearby trawled areas. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2099https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2099Tue, 22 Oct 2019 08:41:27 +0100Collected Evidence: Collected Evidence: Cease or prohibit dredging Four studies examined the effects of ceasing or prohibiting dredging on subtidal benthic invertebrate populations. One study was in the North Atlantic Ocean (Portugal), one in the South Atlantic Ocean (Argentina), one in the English Channel and one in the Irish Sea (UK).   COMMUNITY RESPONSE (3 STUDIES) Overall community composition (3 studies): One of three site comparison studies (one replicated, one before-and-after) in Atlantic Ocean and the Irish Sea found that after ceasing dredging, overall invertebrate community composition was different to that in dredged areas. The other two found that communities remained similar in dredged and non-dredged areas. Overall richness/diversity (3 studies): One of three site comparison studies (one replicated, one before-and-after) in Atlantic Ocean and the Irish Sea found that after ceasing dredging, large (macro-) invertebrate diversity was higher but small (meio-) invertebrate diversity was lower compared to dredged areas. The other two found that overall diversity remained similar in dredged and non-dredged areas. POPULATION RESPONSE (3 STUDIES) Overall abundance (3 studies): One of three site comparison studies (one replicated, one before-and-after) in Atlantic Ocean and the Irish Sea found that four years after ceasing dredging, large (macro-) and small (meio-) invertebrate abundance and/or biomass appeared higher to that in dredged areas. The other two found that abundance and/or biomass remained similar in dredged and non-dredged areas after either two or six years. Tunicate abundance (1 study): One replicated, site comparison study in the English Channel found that a year after ceasing dredging in three areas, abundance of ascidians/sea squirts (tunicates) was similar to that in dredged areas. Bryozoan abundance (1 study): One replicated, site comparison study in the English Channel found that a year after ceasing dredging in three areas, abundance of bryozoan was higher than in dredged areas. Crustacean abundance (1 study): One replicated, site comparison study in the English Channel found that a year after ceasing dredging in three areas, abundance of spider crabs was higher than in dredged areas, but abundance of edible crab was similar. Cnidarian abundance (1 study): One replicated, site comparison study in the English Channel found that a year after ceasing dredging in three areas, abundance of sea fans was higher than in dredged areas. Sponge abundance (1 study): One replicated, site comparison study in the English Channel found that a year after ceasing dredging in three areas, abundance of sponges was higher than in dredged areas. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2101https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2101Tue, 22 Oct 2019 08:53:41 +0100Collected Evidence: Collected Evidence: Cease or prohibit all towed (mobile) fishing gear Eight studies examined the effects of ceasing or prohibiting all towed fishing gear on subtidal benthic invertebrate populations. One study was in the Limfjord (Denmark), two in the English Channel (UK), three in Georges Bank in the North Atlantic Ocean (USA and Canada), one in the Ria Formosa lagoon (Portugal), and one in the Irish Sea (Isle of Man).   COMMUNITY RESPONSE (4 STUDIES) Overall community composition (3 studies): Two of three replicated, site comparison studies in the Limfjord and the English Channel, found that areas excluding towed fishing gear for either an unspecified amount of time or two to 23 years had different overall invertebrate community composition compared to areas where towed-fishing occurred and one found that ceasing towed-gear fishing for nine years had mixed effects. Overall species richness/diversity (3 studies): Two replicated, site comparison studies in the English Channel reported that areas excluding towed fishing gear for either an unspecified amount of time or two to 23 years had different or greater invertebrate species richness and diversity to areas where towed-fishing occurred. One site comparison study in Georges Bank found no difference in invertebrate species richness between an area closed to mobile fishing gear for 10 to 14 years and a fished area. POPULATION RESPONSE (3 STUDIES) Overall abundance (3 studies): Two site comparison studies (one replicated) in the English Channel and Georges Bank found that sites excluding towed gear for either two to 23 years or 10 to 14 years had greater overall invertebrate biomass compared to sites where towed-gear fishing occurred, but one also found that abundance was similar in both areas. One replicated, controlled, before-and-after study in the Ria Formosa lagoon found that ceasing towed gear for 10 months led to increases in the cover of mobile but not sessile Mollusc abundance (2 studies): Two site comparison studies (one replicated) in the Irish Sea and the English Channel found that areas closed to towed fishing gear for either two to 23 years or 14 years had more scallops compared to adjacent fished areas. Mollusc condition (1 study): One site comparison study the Irish Sea found that an area closed to towed fishing gear for 14 years had higher proportions of older and larger scallops compared to an adjacent fished area. Starfish abundance (1 study): One replicated, site comparison study in Georges Bank found more starfish in areas closed to towed fishing gear for five to nine years compared to adjacent fished areas. Starfish condition (1 study): One replicated, site comparison study in Georges Bank found that starfish arm length was similar in areas closed to towed fishing gear for five to nine years and adjacent fished areas. OTHER (1 STUDY) Overall community biological production (1 study): One before-and-after, site comparison study in Georges Bank found an increase in the biological production from invertebrate in sites closed to towed fishing gear for approximately five years compared to adjacent fished sites. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2102https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2102Tue, 22 Oct 2019 08:58:29 +0100Collected Evidence: Collected Evidence: Modify the design of dredges Six studies examined the effects of modifying the design of dredges on subtidal benthic invertebrate populations. Four were in the North Atlantic Ocean (Portugal) and two were in the Irish Sea (Isle of Man).   COMMUNITY RESPONSE (1 STUDY) Unwanted catch overall composition (1 study): One replicated, controlled, study in the Irish Sea found that a new design of scallop dredge caught a similar species composition of unwanted catch to a traditional dredge. POPULATION RESPONSE (3 STUDIES) Overall abundance (2 studies): One of two controlled studies in the North Atlantic Ocean and in the Irish Sea found that a new dredge design damaged or killed fewer invertebrates left in the sediment tracks following dredging. The other found no difference in total invertebrate abundance or biomass living in or on the sediment tracks following fishing with two dredge designs. Unwanted catch overall abundance (2 studies): Two controlled studies (one replicated) in the North Atlantic Ocean and the Irish Sea found that a modified or a new design of bivalve dredge caught less unwanted catch compared to traditional unmodified dredges. Unwanted catch condition (6 studies): Six controlled studies (one replicated and paired, four replicated) in the North Atlantic Ocean and the Irish Sea found that new or modified bivalve dredges damaged or killed similar proportions of unwanted catch (retained and/or escaped) compared to traditional or unmodified designs, three of which also found that they did not reduce the proportion of damaged or dead unwanted crabs (retained and/or escaped). OTHER (1 study) Commercial catch abundance (1 study): One replicated, controlled, study in the Irish Sea found that a new dredge design caught a similar amount of commercially targeted queen scallops compared to a traditional dredge. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2119https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2119Tue, 22 Oct 2019 09:59:43 +0100Collected Evidence: Collected Evidence: Fit one or more mesh escape panels/windows to trawl nets Seven studies examined the effects of adding one or more mesh escape panels/windows to trawl nets on subtidal benthic invertebrate populations. Six were in the North Sea (Belgium, Netherlands, UK), two in the Thames estuary (UK), one in the English Channel (UK), and one in the Gulf of Carpentaria (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (7 STUDIES) Overall survival (1 study): One replicated, paired, controlled study in the English Channel and the North Sea found that fitting nets with either one of seven designs of square mesh escape panels (varying mesh size and twine type) led to higher survival rates of invertebrates that escaped the nets compared to unmodified nets. Unwanted catch overall abundance (7 studies): Three of seven replicated, paired, controlled studies in the North Sea, the Thames estuary, the English Channel and the Gulf of Carpentaria  found that trawl nets fitted with one or more mesh escape panels/windows/zones reduced the unwanted catch of invertebrates compared to unmodified nets. Two found mixed effects of fitting escape panels on the unwanted catch of invertebrates and fish depending on the panel design. Two found that trawl nets fitted with escape panels  caught similar amounts of unwanted invertebrates and fish compared to unmodified nets. OTHERS (7 STUDIES) Commercially targeted catch abundance (7 studies): Three of seven replicated, paired, controlled studies in the North Sea, the Thames estuary, the English Channel and the Gulf of Carpentaria, found that trawl nets fitted with one or more mesh escape panels/windows/zones caught similar amounts of all or most commercial species to unmodified nets. Three found mixed effects of fitting escape panels on the catch of all or most commercial species depending on the species and/or panel design. One found that trawl nets fitted with escape panels reduced the catch of commercial species compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2132https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2132Tue, 22 Oct 2019 10:33:29 +0100Collected Evidence: Collected Evidence: Leave a fallow period during fish/shellfish farming Three studies examined the effects of leaving a fallow period during fish farming on subtidal benthic invertebrate populations. Two studies were in the Tasman Sea (Australia), and one in the North Pacific Ocean (USA).   COMMUNITY RESPONSE (3 STUDIES) Overall community composition (2 study): Two replicated, before-and-after, site comparison study in the Tasman Sea found that after a fallow period invertebrate community composition became similar to that occurring before the fish were added but remained different to communities at sites without fish farms. Worm community composition (1 study): One replicated, before-and-after, site comparison study in the North Pacific Ocean found that after a fallow period polychaete worm community composition changed but remained different to communities at sites without fish farms. Worm richness/diversity (1 study): One replicated, before-and-after, site comparison study in the North Pacific Ocean found that after a fallow period polychaete worm diversity did not change and remained lower compared to sites without fish farms. POPULATION RESPONSE (2 STUDIES) Worm abundance (2 studies): Two replicated, before-and-after, site comparison studies in the Tasman Sea and the North Pacific Ocean found that following a fallow period, abundances of pollution-indicator polychaete worms decreased, but remained higher compared to sites without fish farms. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2191https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2191Tue, 22 Oct 2019 13:02:17 +0100Collected Evidence: Collected Evidence: Restrict the use of tributyltin or other toxic antifouling coatings Four studies examined the effects of restricting the use of tributyltin as an antifouling coating on subtidal benthic invertebrate populations. One study was located in the English Channel (UK), two in the River Crouch estuary (UK), and one in Otsuchi Bay (Japan).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One replicated, before-and-after study in the River Crouch estuary found that after restricting the use of tributyltin, invertebrate community composition changed, but that changes varied with locations. Overall richness/diversity (1 study): One replicated, before-and-after study in the River Crouch estuary found that after restricting the use of tributyltin, overall invertebrate species richness and diversity increased. POPULATION RESPONSE (2 STUDIES) Molluscs condition (1 study): One replicated, before-and-after study in the English Channel found that after restricting the use of tributyltin, there was a decrease in its concentration in dogwhelks and the penis length of female dogwhelks. Crustacean condition (1 study): One study in Otsuchi Bay found that after restricting the use of tributyltin its concentration decreased in skeleton shrimps. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2214https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2214Tue, 22 Oct 2019 13:30:42 +0100Collected Evidence: Collected Evidence: Designate a Marine Protected Area and prohibit all types of fishing Thirty studies examined the effects of prohibiting all types of fishing in marine protected areas on subtidal benthic invertebrate populations. Four studies were systematic reviews of marine reserves (New Zealand and across the world). Two studies were in the North Atlantic Ocean (Bahamas). Five were in the South Pacific Ocean (New Zealand, French Polynesia). Three were in the North Pacific Ocean (USA). Seven were in the Tasman Sea (New Zealand, Australia). One was in the Florida Keys (USA). One was in the Coral Sea (Australia). Three were in the Mediterranean Sea (Italy, Spain). One was in the Bristol Channel and the Irish Sea (UK). Two were in the Firth of Clyde (UK). One was in the Foveaux Straight (New Zealand).   COMMUNITY RESPONSE (5 STUDIES) Overall community composition (3 studies): Three site comparison studies (one replicated and paired, one replicated, one paired) in the Mediterranean Sea, the Tasman Sea, and the Firth of Clyde found that marine protected areas that had been prohibiting all fishing for five to 16 years depending on the study, had similar combined algae, invertebrate and fish community composition, similar combined mollusc and echinoderm community composition, and similar overall community composition of large invertebrates but different composition of small sessile invertebrates, compared to fished areas. Overall species richness/diversity (5 studies): One global systematic review, and three site comparison studies (one replicated and paired, one replicated, one paired) in the Mediterranean Sea, the Tasman Sea, and the Firth of Clyde found that marine protected areas that had been prohibiting all fishing for five to 16 years depending on the study, had similar overall invertebrate species richness/diversity, similar combined algae, invertebrate and fish species richness, and similar combined mollusc and echinoderm species richness, compared to fished areas. One site comparison study in the Tasman Sea found inside a marine protected area prohibiting all mobile fishing that macroinvertebrate species richness remained stable over the 15 years after its designation and enforcement, but decreased at fished sites. POPULATION RESPONSE (2 STUDIES) Overall abundance (4 studies): Two systematic reviews of marine protected areas across the world prohibiting all fishing found that they had greater overall invertebrate abundance and biomass compared to fished areas. Two site comparison studies (one before-and-after, one replicated) in the Tasman Sea found that inside marine protected areas prohibiting all fishing, overall invertebrate abundance did not change over the 15 years after their designation and enforcement and that it did not change in fished areas either, and that all areas had similar combined mollusc and echinoderm abundance after 16 years. Overall condition (1 study): One global systematic review found that in marine protected areas prohibiting all fishing, invertebrates were bigger compared to fished areas. Crustacean abundance (17 studies): Two reviews (one global and systematic, one of New Zealand areas) found that marine protected areas prohibiting all fishing had more lobsters compared to marine protected areas only partially prohibiting fishing and unrestricted fished areas. Eleven of 15 site comparison studies (including replicated, randomized, paired, before-and-after) in the North Atlantic Ocean, the Bristol Channel and the Irish Sea, the Firth of Clyde, the Mediterranean Sea, the North Pacific Ocean, the Florida Keys, the South Pacific Ocean, the Tasman Sea, and the Coral Sea found that inside marine protected areas prohibiting all fishing, the abundances and/or biomasses of lobsters and mud crabs were higher compared to areas where seasonal or unrestricted fishing was allowed, after four to 33 years depending on the study. Four found that they had mixed effects on the abundances of lobster, and crab species, after one to seven years depending on the study. Two found that they had similar abundance of lobsters compared to fished areas after either five to seven years or after approximately 30 years.  Crustacean reproductive success (4 studies): Two site comparison studies (one replicated, randomized) in the Florida Keys and the Firth of Clyde found that marine protected areas prohibiting all fishing and harvesting had similar population sex ratios of lobsters compared to where seasonal fishing or all fishing was allowed, after four to seven years depending on the study. Two replicated, site comparison studies (one randomized) in the Tasman Sea and the Mediterranean Sea found that marine protected areas prohibiting all fishing had greater lobster egg production potential compared to commercial fishing exclusion zones and fully fished areas, after either 15 years or 21 to 25 years. One site comparison study in the Firth of Clyde found that marine protected areas prohibiting all fishing had more female lobsters with eggs than fished areas, after four to seven years. Crustacean condition (8 studies): One review of studies in New Zealand, and five of seven site comparison studies (four replicated, one replicated and randomized) in the North Atlantic Ocean, the Bristol Channel and the Irish Sea, the Firth of Clyde, the Florida Keys, the South Pacific Ocean, the Coral Sea, and the Tasman Sea, found that marine protected areas prohibiting all fishing had bigger lobsters and crabs compared to seasonally fished or fully fished areas, after four to seven years depending on the study. Three found mixed effects on lobsters and crabs depending on species, sex, and locations, after one to seven years depending on the study. Crustacean population structure (2 studies): Two replicated site comparison studies (one randomized) in the Tasman Sea and the Mediterranean Sea found that marine protected areas prohibiting all fishing had different population size structures of lobsters compared to commercial fishing exclusion zones (only for females) and compared to fished areas, after either 15 years or 21 to 25 years. Echinoderm abundance (3 studies): Two of three site comparison studies (two replicated, one paired) in the North Pacific Ocean, the South Pacific Ocean, and the North Pacific Ocean, found that marine protected areas prohibiting all fishing had similar abundance of Kina sea urchins after more than 10 years, and sea cucumbers after eight years to fished areas, and a third found higher abundance of red sea urchins after approximately 30 years. One also found that the effects on abundance of red sea urchins depended on the age of the protected area and the size of the urchins. Echinoderm condition (1 study): One paired, site comparison study in the South Pacific Ocean found that marine protected areas that had been prohibiting all fishing for over 10 years had heavier Kina sea urchins compared to fished areas. Mollusc abundance (10 studies): Four of 10 site comparison studies (including replicated before-and-after, and site comparison) in the North Atlantic Ocean, the North Pacific Ocean the South Pacific Ocean, the Tasman Sea, and the Foveaux Straight found that inside a marine reserve prohibiting all fishing, abundances/biomass of giant clams, adult queen conch, Cook’s turban snails, rock scallops and green abalone were higher compared to a fished area, after eight to 36 years depending on the study. Six found similar abundances of scallop species, pink abalone, juvenile queen conch, and top shell species, after five to 36 years depending on the study. Three found lower abundances of star limpets after 23 to 25 years and blacklip abalone after 15 to 16 years. One found that the effects of marine protected areas prohibiting all fishing on the abundance of mussel species compared to a commercial fishing exclusion zone varied with the age and location of the protected areas. Mollusc reproductive success (1 study): One site comparison study in the North Atlantic Ocean found that inside a marine protected area that had been prohibiting all fishing for 33 to 36 years, abundance of queen conch larvae was higher compared to an unprotected fished area. Mollusc condition (1 study): One site comparison study in the North Pacific Ocean found that in marine protected areas that had been prohibiting all fishing pink abalone were bigger five to 23 years after their designation, compared to fished site. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2224https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2224Tue, 22 Oct 2019 14:04:19 +0100Collected Evidence: Collected Evidence: Designate a Marine Protected Area and prohibit bottom trawling Three studies examined the effects of prohibiting bottom trawling in marine protected areas on subtidal benthic invertebrates. Two studies were in the South Pacific Ocean (Australia) and one in the Coral Sea (Australia).   COMMUNITY RESPONSE (3 STUDIES) Overall community composition (2 studies): One of two replicated, site comparison studies in the South Pacific Ocean found that seamounts within a protected area closed to trawling had different invertebrate community composition compared to trawled seamounts and to never-trawled seamounts after four to nine years. The second study found that seamounts within a protected area closed to trawling had different invertebrate community composition compared to shallow unprotected seamounts (heavily trawled) after two years, but not compared to deep unprotected seamounts (lightly trawled). Overall diversity/species richness (3 studies): One of two replicated, site comparison studies in the South Pacific Ocean found that seamounts within a protected area closed to trawling had similar invertebrate species richness and diversity to trawled seamounts and never-trawled seamounts after four to nine years. The second study found that seamounts within a protected area closed to trawling had more invertebrate species compared to shallow unprotected seamounts (heavily trawled) after two years, but not compared to deep unprotected seamounts (lightly trawled). One randomized, replicated, site comparison study in the Coral Sea found similar combined invertebrate and fish species richness in areas closed to trawling and adjacent fished areas, after seven to eight years. POPULATION RESPONSE (3 STUDIES) Overall abundance (3 studies): One of two replicated, site comparison studies in the South Pacific Ocean found that seamounts within a protected area closed to trawling had lower invertebrate biomass compared to trawled seamounts and never-trawled seamounts after four to nine years. The second study found that seamounts within a protected area closed to trawling had higher invertebrate biomass compared to shallow unprotected seamounts (heavily trawled) after two years, but not compared to deep unprotected seamounts (lightly trawled). One randomized, replicated, site comparison study in the Coral Sea found similar invertebrate and fish biomass in areas closed to trawling and adjacent fished areas, after seven to eight years. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2226https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2226Tue, 22 Oct 2019 15:03:50 +0100Collected Evidence: Collected Evidence: Designate a Marine Protected Area with a zonation system of activity restrictions Thirteen studies examined the effects of designating a marine protected area with a zonation system of activity restrictions on subtidal benthic invertebrate populations. Four studies were in the Caribbean Sea (Belize, Mexico), three in the Mediterranean Sea (Italy), one in the Central Pacific Ocean (Ecuador), three in the Bristol Channel and the Irish Sea (UK), one in the Indian Ocean (Australia), and one in the North Atlantic Ocean (Portugal).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One site comparison study in the Mediterranean Sea found that inside a marine protected area with a zonation system, the combined invertebrate and algae species community composition was different at a site prohibiting all fishing compared to sites where some fishing occurs, after six years. Overall species richness/diversity (1 study): One site comparison study in the North Atlantic Ocean found that inside a marine protected area with a zonation system, sites prohibiting nearly all fishing had similar invertebrate species richness to sites where fishing was mostly allowed, after two years. POPULATION RESPONSE (13 STUDIES) Overall abundance (1 study): One site comparison study in the North Atlantic Ocean found that inside a marine protected area with a zonation system, abundances of specific invertebrate groups varied between sites prohibiting nearly all fishing and sites where fishing was mostly allowed, after two years. Crustacean abundance (7 studies): Three of seven site comparison studies (two replicated) in the Caribbean Sea, the Central Pacific Ocean, and in the Bristol Channel and the Irish Sea found that inside a marine protected area with a zonation system, abundance and/or biomass of spiny lobsters increased in a zone closed to all/commercial fishing and were greater than in a zone where fewer fishing restrictions occurred, after four to 20 years depending on the study. One found that sites closed to all fishing had higher abundances of spiny lobsters and slipper lobsters after eight to ten years compared to fished sites. Two found that sites closed to all fishing for six to seven years had more European lobsters than sites where potting was allowed. And one found that abundances of European lobsters, velvet crabs, brown crabs and spider crabs, after one to four years, varied with the levels of protection. Crustacean condition (4 studies): Three of five site comparison studies (one replicated) in the Bristol Channel and the Irish Sea, and in the Caribbean Sea found that, inside a marine protected area with a zonation system, sites prohibiting all fishing for seven years or commercial fishing (duration unspecified) had bigger lobsters compared to fished areas. One found that the sizes of lobsters, velvet crabs, brown crabs and spider crabs varied with the levels of protection, and one study found that the size of spiny lobsters decreased similarly in an area prohibiting all fishing and in an area with fewer restrictions 14 to 20 years after designation of the protected area. Two studies undertaken in the same area found conflicting effects of prohibiting all fishing for six to seven years on disease and injury of lobsters. Echinoderm abundance (2 studies): One of two site comparison studies in the Mediterranean Sea found that inside a marine protected area with a zonation system, at a site prohibiting all fishing for 17 to 18 years, abundances of two species of sea urchins were higher than at sites allowing the recreational fishing of purple sea urchins. The other one found similar abundance of purple sea urchins inside fully protected sites, sites where some restricted urchin harvest occurs, and unprotected fished sites outside the protected area after five years. Echinoderm condition (2 studies): Two site comparison studies in the Mediterranean Sea found that inside a marine protected area with a zonation system, sites prohibiting all fishing had bigger sea urchins compared to sites where some restricted urchin harvest occurs and compared to unprotected fished sites outside the protected area, after either four years or 17 to 18 years. Mollusc abundance (3 studies): One replicated, randomized, controlled study in the Indian Ocean found that inside a marine protected area with a zonation system, abundance of blacklip abalone was higher in sites that had been prohibiting all fishing for five years compared to those prohibiting commercial fishing only. Two site comparison studies in the Caribbean Sea found that inside marine protected areas with a zonation system, abundances of adult queen conch increased over time in a zone closed to all fishing and were greater than in zones with fewer restrictions, but abundances of juvenile conch did not differ or vary differently between zones, after either five to eight years or 14 to 20 years. Mollusc condition (1 study): One site comparison study in the Caribbean Sea found that inside a marine protected area with a zonation system, the size of queen conch decreased similarly in the area prohibiting all fishing and in the area with fewer restrictions, after 14 to 20 years. Sponge abundance (1 study): One site comparison study in the Mediterranean Sea found that inside a marine protected area with a zonation system, the cover of sponges Cliona was higher at a site prohibiting all fishing for six years compared to sites where some fishing occurred. BEHAVIOUR (1 STUDY) Crustacean behaviour (1 study): One site comparison study in the Caribbean Sea found that, inside a marine protected area with a zonation system (year of designation unspecified), 80% of the lobster population occurring in the unfished area remained in the protected unfished area, and thus remained protected. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2230https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2230Tue, 22 Oct 2019 15:21:24 +0100Collected Evidence: Collected Evidence: Designate a Marine Protected Area and introduce some fishing restrictions (types unspecified) Four studies examined the effects of introducing unspecified types of fishing restrictions in marine protected areas on subtidal benthic invertebrate populations. Two studies were in the Indian Ocean (Seychelles, South Africa), one was a global systematic review, and one was in the Mediterranean Sea (Italy).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (2 studies): One of two site comparison studies (one replicated) in the Indian Ocean and the Mediterranean Sea found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had a different combined invertebrate and algae community composition, while the other (time since designation unspecified) found similar compositions compared to fished areas. POPULATION RESPONSE (3 STUDIES) Overall abundance (1 study): One replicated, site comparison study in the Mediterranean Sea found that a marine protected area with unspecified fishing restrictions had similar invertebrate abundance compared to unprotected fished areas (time since designation unspecified). Bryozoan abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had similar abundance of bryozoans compared to fished areas. Crustacean abundance (1 study): One global systematic review found that marine protected areas with unspecified fishing restrictions had more lobsters compared to fished areas. Echinoderm abundance (2 studies): One of two site comparison studies (one replicated) in the Indian Ocean found that marine protected areas with unspecified fishing restrictions had more sea cucumbers after more than 20 years but the other found fewer sea lilies (year of designation unspecified) compared to fished areas. Hydrozoan abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had more hydrozoans compared to fished areas. Mollusc abundance (1 study): One global systematic review found that marine protected areas with unspecified fishing restrictions had more scallops compared to fished areas. Sponge abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had more sponges compared to fished areas. Tunicate abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area closed to fishing with unspecified fishing restrictions (year of designation unspecified) had similar abundance of ascidians/sea squirts (tunicates) compared to fished areas. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2239https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2239Wed, 23 Oct 2019 08:34:15 +0100Collected Evidence: Collected Evidence: Restore biogenic habitats (other methods) - Restore oyster reefs Eight studies examined the effects of restoring oyster reefs (not by transplanting or translocating oysters) on oysters and oyster reef-associated subtidal benthic invertebrates. Two were in the Gulf of Mexico (USA), one was a global review, four were in the North Pacific Ocean (USA), and one was in the Mission-Aransas estuary (USA).   COMMUNITY RESPONSE (3 STUDIES) Overall community composition (2 studies): One of two replicated, controlled studies in the Gulf of Mexico and the Mission-Aransas estuary found that after restoring eastern oyster reefs, the community composition of combined mobile decapod invertebrates and fish was similar on all types of restoration material used, but the other found that composition varied with the material used. Overall species richness/diversity (3 studies): One replicated, site comparison study in the Gulf of Mexico found that diversity of reef-associated invertebrates was similar in reefs restored by laying rocks regardless of age, in young reefs restored by laying oyster shells, and in natural reefs, but lower in old shell-restored reefs. One replicated, controlled study in the Gulf of Mexico found that diversity of reef-associated invertebrates was higher in all restored reefs than on unrestored sediment, but that diversity varied between the restoration materials used. One replicated, controlled study in the Mission-Aransas estuary found that diversity of fish, crabs and shrimps varied with the restoration material used. POPULATION RESPONSE (7 STUDIES) Overall abundance (2 studies): One replicated, site comparison study in the Gulf of Mexico found that the effect of restoring eastern oyster reefs on the abundance of reef-associated invertebrates depended on the material used for restoration and the age of the reef. One replicated, controlled study in the Gulf of Mexico found that abundance of combined reef-associated mobile decapod invertebrate and fish was similar on all restored reefs regardless of the restoration material used, and higher than on unrestored sediment. Crustacean abundance (1 study): One replicated, controlled study in the Mission-Aransas estuary found that after restoring eastern oyster reefs, crab abundance, but not biomass, and shrimp biomass, but not abundance, varied with the restoration material used. Oyster abundance (6 studies): One replicated, site comparison study in the Gulf of Mexico found that oyster reefs restored by laying rocks had similar oyster abundance to natural reefs, and higher than reefs restored by laying oyster shells. One replicated, controlled study in the Mission-Aransas estuary found that oyster cover and abundance varied with the restoration material used. One replicated, controlled study in the Gulf of Mexico found that oyster spat abundance was similar on all types of restoration material used, and higher than on unrestored sediment. Three replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher cover of clam shells by oysters than when placing the lines above MLLW, that for those placed below MLLW, keeping them there led to similar cover compared to moving them above MLLW halfway through the study, and that placing the lines on cobbly seabed led to similar cover compared to placing them on muddy seabed. Oyster reproductive success (3 studies): Three replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher recruitment of oyster spat on clam shells than by lacing lines above MLLW, that recruitment was higher on lines placed on cobbly seabed than on muddy seabed, and that recruitment was similar on lines placed near or far from the nearest adult oyster populations. Oyster survival (5 studies): One global systematic review found that two of nine restoration techniques (restoring oyster reef by transplanting juveniles, and by creating no-harvest sanctuaries) assessed resulted in over 85% survival of restored oysters. Four replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to similar survival of oysters than when placing the lines above MLLW, but that for those placed below MLLW, moving them above MLLW halfway through the study led to higher survival than keeping then below, that survival was similar on lines placed on cobbly seabed or muddy seabed, and that survival was similar on lines placed near or far from the nearest adult oyster populations. Oyster condition (5 studies): One replicated, controlled study in the Gulf of Mexico found that the effect of restoring eastern oyster reefs on average spat size varied with the restoration material used. One replicated, controlled study in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to similar growth of oysters on the shells than placing lines above MLLW. Four replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher cover of clam shells by non-native species than placing lines above MLLW, but that for those placed below MLLW, moving them above MLLW halfway through the study led to lower cover than keeping then below, that cover was similar on lines placed on cobbly seabed or muddy seabed, and that cover of clam shells by non-native species was higher on lines placed near compared to far from the nearest adult oyster populations. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2248https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2248Wed, 23 Oct 2019 09:37:47 +0100Collected Evidence: Collected Evidence: Restore biogenic habitats (other methods) - Restore seagrass beds/meadows Three studies examined the effects of restoring seagrass beds (not by transplanting or translocating seagrass) on seagrass bed-associated subtidal benthic invertebrates. One was in the North Atlantic Ocean (USA), one in the Indian Ocean (Kenya), and one in the Florida Keys (USA).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One randomized, replicated, controlled study in the Florida Keys found that restoring seagrass beds by fertilizing the seabed had no effect on overall invertebrate community composition, but adding sand led to communities different from both unrestored and natural sites. Overall species richness/diversity (2 studies): One randomized, replicated, controlled study in the Florida Keys found that after restoring seagrass beds by fertilizing the seabed and adding sand, overall invertebrate species richness was similar at restored, unrestored, and natural sites. One replicated, controlled study in the Indian Ocean found that transplanting plastic seagrass mimics into bare sites, previously-restored seagrass sites, and natural seagrass sites, resulted in similar invertebrate diversity on mimic leaves and in the surrounding sediment, and similar species richness on mimic leaves at all restored sites as on natural seagrass leaves. POPULATION RESPONSE (3 STUDIES) Overall abundance (3 studies): One replicated, randomized, controlled, before-and-after study in the North Atlantic Ocean found that after restoring seagrass beds, the abundance of mobile invertebrates had increased and was higher in restored than unrestored plots, but the abundance of sessile invertebrates had not increased. One replicated, controlled study in the Indian Ocean found that transplanting plastic seagrass mimics into bare sites, previously-restored seagrass sites, and natural seagrass sites, resulted in similar abundance of invertebrate in the surrounding sediment across sites, and resulted in different abundance of invertebrates on mimic leaves between sites although all had lower abundances than on natural seagrass leaves. One randomized, replicated, controlled study in the Florida Keys found that after restoring seagrass beds by fertilizing the seabed or adding sand, overall invertebrate abundance was not different at restored sites compared to both unrestored and natural sites. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2249https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2249Wed, 23 Oct 2019 09:45:10 +0100Collected Evidence: Collected Evidence: Restore coastal lagoons Three studies examined the effects restoring coastal lagoons on subtidal benthic invertebrate populations. One study was in the Chilika lagoon (India), and two in East Harbor lagoon (USA).   COMMUNITY RESPONSE (3 STUDIES) Crustacean richness/diversity (1 study): One before-and-after study in Chilika lagoon found that following hydrological restoration total crustacean species richness decreased, but changes varied with species groups (decreases in prawn and crab species; increases in lobster species). The lagoon also hosted new species not found before. Mollusc richness/diversity (2 studies): Two studies in East Harbor lagoon found that following hydrological restoration molluscs recolonised the lagoon and their species richness increased in the first three years but later decreased over the following six. POPULATION RESPONSE (3 STUDIES) Crustacean abundance (1 study): One before-and-after study in Chilika lagoon found that following hydrological restoration abundances of prawns and crabs increased. Mollusc abundance (2 studies): Two studies in East Harbor lagoon found that following hydrological restoration molluscs recolonised the lagoon and their total abundance increased in the first three years, but later decreased over the following six. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2250https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2250Wed, 23 Oct 2019 09:48:44 +0100Collected Evidence: Collected Evidence: Provide artificial shelters Five studies examined the effects of providing artificial shelters on subtidal benthic invertebrates. Three studies were in the Caribbean Sea (Mexico); one in Florida Bay and one in the Florida Keys (USA).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Lobster abundance (2 studies): Two replicated, controlled, before-and-after studies in the Caribbean Sea found that abundance of lobsters either increased in plots with artificial shelters but not in plots without, or increased in all plots but more so in plots with artificial shelters than those without. Lobster condition (1 study): One replicated, controlled, before-and-after study in the Caribbean Sea found that lobsters in plots with artificial shelters were bigger than in plots without. BEHAVIOUR (3 STUDIES) Use (3 studies): Three replicated studies (two controlled) in Florida Bay, the Florida Keys, and the Caribbean Sea, found that artificial shelters were occupied by lobsters and molluscs, that occupancy by lobsters varied with artificial shelter designs, that lobsters occupied artificial shelters more than natural ones (crevices), and that lobsters occupying artificial shelters were larger, had greater nutritional condition, and had similar sex ratio and survival rate, compared to lobsters occupying natural shelters. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2257https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2257Wed, 23 Oct 2019 10:13:10 +0100Collected Evidence: Collected Evidence: Create artificial reefs Twelve studies examined the effects of creating artificial reefs on subtidal benthic invertebrate populations. Three studies were in the Mediterranean Sea (Italy); three were in the North Atlantic Ocean (USA, Portugal, France); one in the Firth of Lorn (UK); two in the North Pacific Ocean (USA); one in the English Channel (UK), one in the Gulf of Mexico (USA); and one in the Yellow Sea (China).   COMMUNITY RESPONSE (8 STUDIES) Overall community composition (3 studies): Two site comparison studies (one replicated) in the English Channel and North Atlantic Ocean found that invertebrate communities growing on artificial reefs were different to that of natural reefs. One replicated study the North Pacific Ocean found that invertebrate community composition changed over time on an artificial reef. Overall richness/diversity (6 studies): Two site comparison studies (one replicated) in the Mediterranean Sea and North Atlantic Ocean found that invertebrate species richness and/or diversity on the artificial reef or in the sediments inside and adjacent to the reef area were lower compared to on natural reefs or in nearby natural sediments. One replicated, site comparison study in the Gulf of Mexico found that artificial breakwaters had more species of nekton compared to adjacent mudflats. One site comparison study in English Channel recorded 263 taxa on the artificial reef, including at least nine not recorded on nearby natural reefs but excluding at least 39 recorded on natural reefs. One replicated study in the North Pacific Ocean found a 49% increase in species richness over five years on an artificial reef. One study in the North Atlantic Ocean found that artificial reefs hosted at least five species of large mobile invertebrates. Mollusc richness/diversity (1 study): One replicated, site comparison study in the Mediterranean Sea found that mollusc species richness and diversity were lower on artificial reefs compared to natural reefs. Worm community composition (1 study): One replicated, site comparison study in the North Pacific Ocean found that polychaete worm community composition was similar at one of two artificial reefs compared to a natural reef. Worm richness/diversity (1 study): One replicated, site comparison study in the North Pacific Ocean found that polychaete worm species richness and diversity were similar at one of two artificial reefs compared to a natural reef, but lower at the second artificial reef. POPULATION RESPONSE (12 STUDIES) Overall abundance (10 studies): One of two site comparison studies (one replicated) in the Mediterranean Sea found that abundance of invertebrates in the sediment was lower at the reef sites than in nearby natural sediments, but increased in the sediments directly adjacent to the reefs, while the other study found that abundance was similar in the sediments inside and directly adjacent to the artificial reef area, but lower than in nearby natural sediments. Of five site comparison studies (four replicated) in the North Pacific Ocean, the North Atlantic Ocean, the Gulf of Mexico and the Yellow Sea, one found that invertebrate biomass was higher on the artificial reef than in adjacent natural sediments, two that invertebrate abundance and biomass and nekton abundance were similar on artificial reefs and natural habitats (reef; mudflat), and two found mixed effects on abundances of invertebrates. One site comparison study in the English Channel reported that the abundances of some species were lower on the artificial reef compared to natural reefs. One replicated study in the North Pacific Ocean reported an 86% increase in invertebrate abundance growing on an artificial reef over five years. One study in the North Atlantic Ocean found that two of five species at one artificial reef, and three of seven at another, were recorded during >50% of dives. Overall condition (1 study): One replicated, site comparison study in the Yellow Sea found mixed effects of creating an artificial reef on the sizes of mobile invertebrates. Mollusc abundance (1 study): One replicated, site comparison study in the Mediterranean Sea found that mollusc abundance was lower on artificial reefs compared to natural reefs. Crustacean abundance (1 study): One replicated, site comparison in the Firth of Lorn found that abundances of edible crabs and velvet swimming crabs were typically higher on artificial than natural reefs. OTHER (1 STUDY) Biological production (1 study): One site comparison study in North Atlantic Ocean found that secondary production was higher from invertebrates growing on an artificial reef than from invertebrates in adjacent natural sediments. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2258https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2258Wed, 23 Oct 2019 10:26:30 +0100Collected Evidence: Collected Evidence: Create artificial reefs of different 3-D structure and material used Eight studies examined the effects of creating artificial reefs of different typology on subtidal benthic invertebrate populations. One study was in the English Channel (UK), three in the Mediterranean Sea (Israel, Italy), one in the North Atlantic Ocean (USA), one in the Firth of Lorn (UK), one in the North Pacific Ocean (USA), and one in the Gulf of Mexico (USA).   COMMUNITY RESPONSE (6 STUDIES) Overall community composition (3 studies): One controlled study in the English Channel found that artificial reef modules made of scrap tyres developed a similar sessile invertebrate community composition as traditional artificial concrete modules. Two controlled studies (one replicated) in the Mediterranean Sea found that pyramids reefs made of “sea-friendly” concrete developed different invertebrate community compositions compared to reefs of either traditional concrete plinth-pole structures or bundles of traditional concrete tubes. Overall richness/diversity (5 studies): Four controlled studies (three replicated) in the Mediterranean Sea, the North Pacific Ocean, and the Gulf of Mexico found no differences in overall invertebrate richness/diversity or combined mobile invertebrate and fish richness between reef structure and/or material. One controlled study in the Mediterranean Sea found that invertebrate species richness was lower on “sea-friendly” pyramid reefs compared to bundle reefs of traditional concrete. POPULATION RESPONSE (7 STUDIES) Overall abundance (5 studies): Four controlled studies (three replicated) in the English Channel, the Mediterranean Sea, the North Pacific Ocean, and the Gulf of Mexico found no differences in overall invertebrate abundances or combined mobile invertebrate and fish abundance between reef structure and/or material. One controlled study in the Mediterranean Sea found that “sea-friendly” concrete pyramids had lower abundance compared to plinth-pole structures after two years, but higher after three. Crustacean abundance (2 studies): One replicated, controlled study in the North Atlantic Ocean found that artificial reefs made of limestone boulders, gravel concrete aggregate, or tyre-concrete aggregate had similar abundance of spiny lobsters. One replicated, controlled study in the Firth of Lorn found that the complexity of artificial reef modules had mixed effects on the abundance of edible crab and velvet swimming crab. Mollusc abundance (1 study): One replicated, controlled study in the Gulf of Mexico found that breakwaters made of bags of oyster shells recruited more oysters and ribbed mussels compared to “ReefBall” breakwaters. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2259https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2259Wed, 23 Oct 2019 10:39:51 +0100Collected Evidence: Collected Evidence: Transplant/release captive-bred or hatchery-reared species - Transplant/release crustaceans Five studies examined the effects of transplanting or releasing hatchery-reared crustacean species on their wild populations. Four examined lobsters in the North Sea (Germany, Norway, UK), and one examined prawns in the Swan-Canning Estuary (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (5 STUDIES) Crustacean abundance (1 study): One study in the Swan-Canning Estuary  found that after releasing hatchery-reared prawn larvae into the wild, the abundance of egg-bearing female prawns increased. Crustacean reproductive success (3 studies): Two studies (one controlled) in the North Sea found that after their release, recaptured hatchery-reared female lobsters carried eggs, and the number, size and developmental stage of eggs were similar to that of wild females. One study in the Swan-Canning Estuary  found that after releasing hatchery-reared prawn larvae into the wild the overall population fecundity (egg production/area) increased. Crustacean survival (2 studies): Two studies in the North Sea found that 50–84% and 32–39% of hatchery-reared lobsters survived in the wild after release, up to eight and up to five years, respectively. Crustacean condition (4 studies): Two studies in the North Sea found that hatchery-reared lobsters grew in the wild after release. One controlled study in the North Sea found that after release into the wild, hatchery-reared female lobsters had similar growth rates as wild females. One study in the North Sea found that after releasing hatchery-reared lobsters, no recaptured lobsters displayed signs of “Black Spot” disease, and 95% had developed a crusher-claw. One study in the Swan-Canning Estuary  found that after releasing hatchery-reared prawn larvae into the wild, the size of egg-bearing female prawns increased. BEHAVIOUR (1 STUDY) Crustacean movement (1 study): One controlled study in the North Sea found that after release into the wild, hatchery-reared female lobsters had similar movement patterns as wild females. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2266https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2266Wed, 23 Oct 2019 12:11:24 +0100Collected Evidence: Collected Evidence: Transplant/release captive-bred or hatchery-reared species - Transplant/release molluscs Eight studies examined the effects of transplanting or releasing hatchery-reared mollusc species on their wild populations. One examined abalone in the North Pacific Ocean (Canada), one examined clams off the Strait of Singapore (Singapore), one examined oysters in the North Atlantic Ocean (USA), and four examined scallops in the North Atlantic Ocean and Gulf of Mexico (USA).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (8 STUDIES) Mollusc abundance (2 studies): One replicated, before-and-after study in the North Atlantic Ocean found that after transplanting hatchery-reared scallops, abundance of juvenile scallops typically increased, but not that of adult scallops. Two replicated, randomized, controlled studies in the North Atlantic Ocean, found that after releasing hatchery-reared oyster larvae, more spat initially settled using a direct technique compared to a traditional remote technique, and equal number of spat settled on cleaned and natural oyster shells. Mollusc reproductive success (1 study): One replicated, before-and-after study in the North Atlantic Ocean found that after transplanting hatchery-reared scallops, larval recruitment increased across all areas studied. Mollusc survival (5 studies): One replicated study in the Strait of Singapore found that, after transplantation in the field, aquarium-reared clams had a high survival rate. One replicated, controlled study in the North Atlantic Ocean found that after transplanting hatchery-reared scallops, the number of transplanted scallops surviving decreased regardless of the methods used, and maximum mortalities was reported to be 0–1.5%. One replicated, controlled study in the North Pacific Ocean found that transplanting hatchery-reared abalone into the wild reduced survivorship compared to non-transplanted hatchery-reared abalone kept in tanks. Two replicated, randomized, controlled studies in the North Atlantic Ocean found that after releasing hatchery-reared oyster larvae, 61% of the settled spat survived the winter, and settled spat survived equally on cleaned and natural oyster shells. Mollusc condition (3 studies): Two replicated studies in the Strait of Singapore and the North Atlantic Ocean found after transplantation in the wild, aquarium-reared clams and hatchery-reared scallops increased in weight and/or grew. Scallops grew in both free-planted plots and suspended bags but grew more in free-planted plots. One replicated, before-and-after study in the Gulf of Mexico found that after transplanting hatchery-reared scallops, wild populations had not become genetically more similar to hatchery-reared scallops. One replicated, controlled study in the North Atlantic Ocean found that after transplanting hatchery-reared scallops, free-planted scallops developed less shell biofouling than suspended scallops. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2267https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2267Wed, 23 Oct 2019 12:16:17 +0100Collected Evidence: Collected Evidence: Translocate species - Translocate molluscs Nine studies examined the effects of translocating mollusc species on their wild populations. Two examined scallops in the North Atlantic Ocean (USA) and one examined scallops in the Tasman Sea and South Pacific Ocean (New Zealand). One study examined conch in the Florida Keys (USA). One examined clams in the North Atlantic Ocean (Portugal). One examined abalone in the North Pacific Ocean (USA). One examined mussels in Strangford Lough (UK). Two examined mussels in the Gulf of Corinth (Greece).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (8 STUDIES) Mollusc abundance (3 studies): One replicated, controlled, before-and-after study in the North Atlantic Ocean found that translocating bay scallops increased larval recruitment into the adult population compared to before translocation. One before-and-after study in the North Pacific Ocean found that following translocation of adult pink abalone to existing patchy populations, total abalone abundance (translocated and resident) decreased to similar levels as before translocation. One replicated, site comparison study in Strangford Lough found that after translocating horse mussels, the abundance of young mussels was higher in site with translocated mussels compared to both sites without translocated mussels and natural mussel reefs. Mollusc reproductive success (1 study): One replicated, controlled, before-and-after study in the North Atlantic Ocean found that translocating bay scallops did not increase larval production compared to before translocation. Mollusc survival (5 studies): Three replicated studies (one before-and-after and two site comparisons) in the North Atlantic Ocean and in the Tasman Sea and South Pacific Ocean, found that following translocation, scallops and clams survived. Survival of translocated New Zealand scallops was higher in areas closed to commercial fishing compared to fished areas. Two studies in the Gulf of Corinth found that Mediterranean fan mussels survived when translocated to a deep site, and had similar survival compared to naturally-occurring mussels, but did not survive when translocated to a shallow site. Mollusc condition (2 studies): One replicated, site comparison study in the North Atlantic Ocean found that following translocation, clams had similar condition indices to clams in the source site. One study in the Gulf of Corinth found that translocated Mediterranean fan mussels had similar size-specific growth-rates compared to naturally-occurring mussels. BEHAVIOUR (1 STUDY) Mollusc behaviour (1 study): One replicated study in the Florida Keys found that translocating non-reproductive adult queen conch to aggregations of reproductive conch did not have adverse effects on the movement patterns of non-translocated resident conch, and all conch displayed similar total distance travelled, movement rates, migration patterns, home-range sizes, and sociability. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2270https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2270Wed, 23 Oct 2019 12:38:40 +0100
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust