Future of Marine Animal Populations - Scientific Highlights

Scientific Highlights

• New discovered method estimates that Earth is home to 8.7 million species, of which 2.1 million live in the ocean.

• Reported severe depletion of large marine animals over the past 50 to 500 years. An up to 90% reduction in the abundance of large, commercially exploited marine megafauna has occurred since human impacts began, along with a reduction of total animal biomass and the local extinction of particular species.
• Identified ecosystem consequences of losing marine biodiversity: changes in abundance and diversity have negatively impacted ecosystem productivity and resilience, and compromised water quality, fishery yields and other ecosystem services. Conservation and management efforts over the last century have halted or even reversed the decline of biodiversity in some areas. Yet in areas where there are few management initiatives in place, the abundance and diversity of marine animal populations continues to decline, mostly in direct relation to multiple human impacts.
• Discovered global patterns of biodiversity for tuna and billfish, sharks, and marine mammals, which are different from those generalized for terrestrial environments.
• Used the entire Census database to identify global hotspots of marine biodiversity across 13 major taxa, and identified water temperature as the main environmental predictor of biodiversity patterns in the ocean. Sea surface temperature was found to be the primary oceanographic driver of marine animal distribution and diversity at global scales.
• Reported a slow, global decline in plankton abundance since the beginning of oceanographic measurements in the late 19th century that appeared to be linked to gradual ocean warming and increased stratification of the water column.
• Examined how marine biodiversity might change over the next 50 years. The future of marine animal populations is likely determined in large part by two key variables: the rate of ocean warming, and the rate of exploitation. Where those rates are low, it will increase the chance for adaptation and recovery. Where they continue to rise, the loss of marine biodiversity and associated services will be severe.
• Developed new methods to better understand the dynamic movement and habitat use of marine animals. Results indicate that spatial patterns of animal behaviours are markedly discrete and predictable both seasonally and inter-annually, implying strong connections to environmental drivers and prey distribution.