Reunite abandoned marine and freshwater mammal young with parents

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
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How is the evidence assessed?

Effectiveness

50%
Certainty

25%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

Dependent marine and freshwater mammal young may be abandoned or become separated from their parents. To increase chances of survival, abandoned young may be rescued and reunited with their parents. For rare or threatened species, this may help to maintain or boost population sizes.

Study locations

Key messages

One study evaluated the effects of reuniting abandoned marine and freshwater mammal young with parents. The study was in the North Pacific Ocean (USA).

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (1 STUDY)

Reproductive success (1 study): One review in the North Pacific Ocean found that after reuniting Hawaiian monk seal pups with their mothers, along with at least seven other interventions to enhance survival, more than a quarter of the seals reproduced.
Survival (1 study): One review in the North Pacific Ocean found that after reuniting Hawaiian monk seal pups with their mothers, along with at least seven other interventions to enhance survival, more than a quarter of the seals survived.

BEHAVIOUR (0 STUDIES)

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

A review of interventions in 1980–2012 for Hawaiian monk seals Monachus schauinslandi in the North Pacific Ocean, Hawaii, USA (Harting et al. 2014) found that reuniting seal pups with their mothers, along with at least seven other interventions to enhance survival, resulted in 139 of 532 (26%) seals surviving and reproducing. The study did not distinguish between the effects of reuniting pups with their mothers and the other interventions carried out. The 139 surviving seals (including 71 females) produced at least 147 pups, which also went on to reproduce (15 pups). In 2012, the number of surviving seals and their offspring were estimated to make up 17–24% of the seal population (198–271 of 1,153 seals). In 1980–2012, a total of 885 intervention events of seven types were carried out: pups reunited with mothers (113 events); removal of derelict fishing gear from seals (275 events); translocation (284 events); rescue of stranded or trapped seals (37 events); umbilical cord removed or other medical treatment (84 events); other actions, such as deterring aggressive male seals (120 events). Field biologists and monitored the seal population in 1980–2012. Data were analysed for 532 individual seals facing severe mortality risks and involved in 698 of the 885 intervention events.
Study and other actions tested
Referenced paper
Harting A.L., Johanos T.C. & Littnan C.L. (2014) Benefits derived from opportunistic survival-enhancing interventions for the Hawaiian monk seal: the silver BB paradigm. Endangered Species Research, 25, 89-96.

Please cite as:

Berthinussen, A., Smith, R.K. and Sutherland, W.J. (2021) Marine and Freshwater Mammal Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Marine and Freshwater Mammal Conservation

Related Actions

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Hand-rear orphaned or abandoned marine and freshwater mammal young Action Link	Trade-off between benefit and harms	12	Synopsis Link
Legally protect marine and freshwater mammal species Action Link	No evidence found (no assessment)	0	Synopsis Link
Remove individual marine and freshwater mammals exhibiting aggressive behaviours that may limit population recovery Action Link	Trade-off between benefit and harms	1	Synopsis Link