Action

Designate a Marine Protected Area and prohibit all types of fishing

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

COMMUNITY RESPONSE (1 STUDY)

  • Richness/diversity (1 study): One replicated, site comparison in the Bahamas and Turks and Caicos Islands found differences in community composition between protected and unprotected areas.

POPULATION RESPONSE (6 STUDIES)

  • Abundance (4 studies): Two of three replicated, site comparison studies in the Bahamas and Turks and Caicos Islands, Guadeloupe and Kenya found that coral cover was similar in protected and unprotected areas. The other study found that cover was higher in protected than in unprotected areas. One of the studies also found that three coral species were found more frequently in protected than in unprotected areas. One replicated, site comparison in Kenya found that density of coral recruits was similar in protected and unprotected areas. This study also found that caging settlement tiles resulted in fewer coral recruits in protected areas (with fish grazers) and more recruits in unprotected areas (with urchin grazers).
  • Survival (1 study): One replicated, controlled study in Belize found that coral mortality was higher in protected than in unprotected areas for one of two transplanted coral species.
  • Condition (2 studies): One replicated, controlled study in Belize found lower growth rates of two transplanted coral species and higher rates of bleaching for one of the two species in protected compared to unprotected areas. One site comparison in Spain found that fewer corals had been colonized by other organisms in protected than in unprotected areas.

 

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A replicated, site comparison study in 2004 in marine sites within Exuma Cays Land and Sea Park in the Bahamas and Turks and Caicos Islands (Harborne et al. 2008) found that in protected areas that prohibited all fishing, there was similar coral cover but higher occurrence of three coral species compared to sites where fishing was allowed. Three species of corals had higher frequency of occurrences within the Exuma Cays reserve compared to outside the reserve (Montastraea franksi inside reserve 50%; outside: 13%; Agaricia agaricites: 74% and 40%; Millepora alcicornis: 47% and 38%). In protected Montastraea reefs the benthic community structure was different compared to similar reefs outside the reserve while fish diversity and abundance of some large-bodied fish were higher in the reserve (see paper for details and data for fish). The Park is a large (442 km2) reserve established in 1958, with fishing bans enforced by warden patrols since 1986. Overall, 21 protected reef sites (150 × 150 m in the centre, on the edge of the reserve and separated between forereef and plain) and five non-protected reef sites near other islands were selected by matching to reduce variability. In 2004, at each site 30–40 randomly placed quadrats (1 m2) were used to quantify the benthic community with coral and macroalgal cover in each quadrat recorded as the average of five randomly sub-sampled areas of 20 × 20 cm.

    Study and other actions tested
  2. A replicated, site comparison study in 2004 in 10 coral reef sites off Guadeloupe in the eastern Caribbean Sea (Kopp et al. 2010) found that in protected areas that prohibited all fishing, coral cover was higher than in unprotected areas. Coral cover was higher in the protected (26%) than unprotected areas (18%). Five reef sites in protected areas were selected (fishing prohibited since 1979 and 1987), along with five unprotected reef sites. In 2004, every site was sampled in the dry and rainy season (May and November respectively). Visual surveys along a 150 × 2 m transect were carried out by divers, with each transect surveyed twice/season. Benthic organisms (including corals) were recorded every meter along the transect.

    Study and other actions tested
  3. A replicated, controlled study in 2003–2004 of 16 patch reefs in Belize (McClanahan et al. 2011) found that in protected areas that prohibited all fishing there was lower growth rates for transplanted corals Siderastrea siderea and Porites astreoides, and higher rates of mortality and bleaching for S. siderea, compared to areas in which fishing was not prohibited. Eighteen months after transplanting, average growth rates were lower in areas where fishing was prohibited compared to areas with fishing for S. siderea (13 vs 28%) and P. astreoides (2 vs 24%). Average bleaching and mortality rates were higher in unfished than fished areas for S. siderea (bleaching: 13 vs 6%; mortality: 15 vs 10%), but there was no significant effect on P. astreoides (data not reported). In January 2003, six ‘fist-sized’ S. siderea and P. astreoides were transplanted onto each of 16 patch reefs (each 25–50 m2) in a marine reserve. Half were in an area in which fishing had been prohibited for eight years, and the other half in an area still fished. Corals were collected from 1–3 km away and attached using masonry cement. Bleached corals were counted monthly, and surviving corals measured every three months, until August 2004.

    Study and other actions tested
  4. A site comparison study in 2010–2011 at nine coral reef sites in Cap de Creus and Medes Islands, off Spain in the northern Mediterranean (Tsounis et al. 2012 ) found that in a protected area that prohibited all fishing and diving, fewer coral Paramuricea clavata colonies had other organisms growing on them (likely due to injury/damage) than in areas where fishing and/or diving was permitted. In the protected area, 4–10% of colonies had other organisms growing on them, compared to 10–33% in unprotected areas. Colonies with organisms growing on them had fewer reproductive cells (5–13 gonads/coral polyp) than those without (10–25 gonads/coral polyp) and differences in concentrations of lipids, carbohydrates and proteins in coral branches (see paper for details). One area of a marine park (established in 1996) where both fishing and diving was prohibited was selected, along with six other sites in the same area (with a mix of recreational fishing and diving) and two sites in different area (with some diving permitted but no fishing). In June 2010 and January 2011, a total of 15 surveys across the nine locations were carried out (4 in the fully protected area) by divers along transects (6–20 m long, 16–38 m deep).

    Study and other actions tested
  5. A replicated, site comparison study in 2007–2008 in six coral reef sites off the coast of Kenya (O'Leary et al. 2013) found that in protected areas that prohibited all types of fishing, the number of coral recruits was similar compared to the number of recruits in fished areas. Overall, average density of coral recruits (live and covered) was not significantly different between protected areas (32 recruits/m2) and fished areas (149 recruits/m2). Authors also reported that caging settlement tiles to exclude grazers after six months had different effects on the number of live recruits in protected areas with fish grazers (caged lower with 70 recruits/m2, uncaged: 140 recruits/m2) and fished areas with urchin grazers (caged higher with 750 recruits/m2, uncaged: 450 recruits/m2). Three well-enforced protected areas were selected where all fishing was prohibited for >15 years, along with three nearby fished reefs. Settlement tiles were deployed in cement blocks at all six sites (4 tiles/block, 16 blocks/site). Two tiles on each block were caged to exclude grazers and two were left uncaged for six months, after which time half of the treatments were switched for a further six months. All coral recruits were counted, including those that were alive and those covered by other organisms.

    Study and other actions tested
  6. A replicated, site comparison study in 2011 at six sites off the coast of Kenya (Humphries et al. 2014) found that protected areas that prohibited all types of fishing had similar coral cover compared to community managed fishery closures and fished areas. Coral cover did not vary based on management type and was 20 and 27% in protected areas, 26 and 46% in community closures, and 7 and 35% in fished areas. Two government closures were protected since 1968 and 1991. Two community managed areas were closed to fishing in 2005 and 2010. Two fished areas were fished intensively with a range of gear (including spearguns, nets, traps). In 2011, coral cover was surveyed using randomly placed 10 m transects (9 transects/site).

    Study and other actions tested
Please cite as:

Thornton A., Morgan, W.H., Bladon E.K., Smith R.K. & Sutherland W.J. (2024) Coral Conservation: Global evidence for the effects of actions. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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Coral Conservation

This Action forms part of the Action Synopsis:

Coral Conservation
Coral Conservation

Coral Conservation - Published 2024

Coral synopsis

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