Researchers conducted the first IUCN-RLE assessment of an offshore marine ecosystem and listed the southern Benguela of South Africa as Endangered.
The IUCN Red List of Ecosystems has made some great strides over the last few years, with over 1,500 ecosystems assessed in 90 countries. However, the application of the protocol to offshore marine ecosystems has been lacking. To date, only 10% of ecosystems listed on the RLE belong to the marine realm.
Current evidence shows that marine ecosystems are at considerable risk from regime shifts, mostly due to fishing and environmental change. However, it is difficult to assess risks to marine ecosystems because unlike most terrestrial ecosystems; offshore marine ecosystems can have highly variable spatial distributions and time series data tend to be scarce.
Focusing on the southern Benguela of South Africa, researchers conducted the first IUCN Red List of Ecosystems assessment of an offshore marine ecosystem. They selected the southern Benguela, one of two similar ecosystems around the African coast - along with the already collapsed northern Benguela (located north in Namibia), to conduct the risk assessment taking advantage of the wealth of information available. This included models of ecosystem functioning from the 1600s to the present, time-series data for different species groups, and expert-derived information on what collapse would look like for this particular ecosystem.
For the first time, a structured expert elicitation (i.e., repeatable estimation by expert judgment) was used to define ecosystem collapse. As a result, the southern Benguela was listed as Endangered in both 2015 and 1960. The results also showed that seabirds are good indicators of marine ecosystem health globally due to how closely they respond to food availability, so focusing on these species may be useful for Red List of Ecosystems assessments of marine ecosystems.
This study shows that it is possible to assess risks to marine ecosystems based on a strong definition of collapse, which can be derived from similar ecosystems; good time series data, from either models or surveys; and ecosystem experts that can bring all this knowledge together into a sound, repeatable risk assessment.
The paper “Assessing risks to marine ecosystems with indicators, ecosystem models and experts” will be published in November 2018 as an Accepted Article in Biological Conservation.
Written by: Lucie Bland
Style and format: Mariana Hernández and Clara Gómez
Provita Sep 20, 2018