Ecosystems in Search of Recovery:  Caribbean, Mediterranean & Baltic Seas

Loren McClenachan1, Francesco Ferretti2, Heike Lotze2, Brian MacKenzie3  & Chato Osio4

1 SCRIPPS  INSTITUTION OF  OCEANOGRAPHY
2 DALHOUSIE  UNIVERSITY
3 TECHNICAL  UNIVERSITY  OF  DENMARK
4 UNIVERSITY OF  NEW  HAMPSHIRE

Abstract
Coastal seas have been degraded over centuries, and populations of marine animals are significantly depleted from historical baseline levels.  A comparison of three Atlantic ecosystems across a gradient of human disturbance and natural productivity indicates that the loss of large predators is a central characteristic of depletion across ecosystems. In particular, reductions in populations of sharks, monk seals and large groupers in the Caribbean Sea, sharks, and monk seals in the Mediterranean Sea, and seals and porpoises on the Baltic Sea have important implications for the past state and future recovery of these coastal seas.

 Despite long-term declines, population recoveries have occurred when fishing pressure is reduced. However, these recoveries take place in ecosystems that are highly altered by fishing and other anthropogenic influences, including climate change, eutrophication, toxic contamination, and disease. Climate change, for example, will affect recovery in both the most temperate and tropical ecosystems. Ice-breeding seals in the Baltic lose habitat as temperatures rise, so that reduced exploitation alone will not guarantee their recovery. In the Caribbean, extreme temperature fluctuations have induced coral bleaching and disease, both of which inhibit recovery of reef-dependent organisms. Recovery efforts in all systems will need to consider both reducing exploitation and eliminating other stressors that inhibit recovery.