A Multi Criteria Assessment Method for Identifying Vulnerable Marine Ecosystems in the North-East Atlantic

Abstract

In international fisheries management, scientific advice on the presence of "vulnerable marine ecosystems" (VMEs) per United Nations resolutions, has generally used qualitative assessments based on expert judgment of the occurrence of indicator taxa such as cold-water corals and sponges. Use of expert judgment alone can be criticized for inconsistency and sometimes a lack of transparency; therefore, development of robust and repeatable numeric methods to detect the presence of VMEs would be advantageous. Here, we present a multi-criteria assessment (MCA) method to evaluate how likely a given area of seafloor represents a VME. The MCA is a taxa-dependent spatial method that accounts for both the quantity and data quality available. This was applied to a database of records of VMEs built, held and compiled by the International Council for the Exploration of the Sea (ICES). A VME index was generated which ranged from 1.51 to 4.52, with 5.0 being reserved for confirmed VME habitats. An index of confidence was also computed that ranged from 0.0 to 0.75, with 1 being reserved for those confirmed VME habitats. Overall the MCA captured the important elements of the ICES VME database and provided a simplified, spatially aggregated, and weighted estimate of how likely a given area is to contain VMEs. The associated estimate of confidence gave an indication of how uncertain that assessment was for the same given area. This methodology provides a more systematic and standardized approach for assessing the likelihood of presence of VMEs in the NorthEast Atlantic.

Significance of Climate Indices to Benthic Conditions Across the Northern North Atlantic and Adjacent Shelf Seas

“…As well as considering spatio-temporal patterns at the basinscale, we examine temporal changes at fourteen case study sites (Figure 1 and Table 1). These sites were chosen to represent a variety of potentially vulnerable deep-sea ecosystems across the northern North Atlantic region as indicated by VME indicator records (Morato et al, 2018). The sites also include a number of existing, or proposed, Marine Protected Areas (MPAs), Ecologically or Biologically Significant Areas (EBSAs), and VME closures (Johnson et al, 2018).…”

“…four sites have maximum depths below 3500 m ( Table 1), there is no site that truly represents the abyssal plains of the North Atlantic south of 50 • N. This reflects the current absence of VME indicator records in these areas (Morato et al, 2018). Time-series were constructed for each case study site.…”

Rockall and Hatton: Resolving a Super Wicked Marine Governance Problem in the High Seas of the Northeast Atlantic Ocean

“…Confidence in the resulting score is then assigned based on four further criteria: survey method (e.g., trawl vs. ROV), number of surveys to the area, the time range of the surveys undertaken, and the time since the last survey. Detailed results of this application are presented in Morato et al (2018).…”

True Size Matters for Conservation: A Robust Method to Determine the Size of Deep-Sea Coral Reefs Shows They Are Typically Small on Seamounts in the Southwest Pacific Ocean

“…The criteria have mostly been applied to "indicator" species, or higher-level taxa, resulting in methods that primarily use the presence of indicator taxa to identify VME locations. These methods have become increasingly quantitative, progressing from relatively simple threshold approaches (e.g., Auster et al, 2011) to multi-criteria mapping that combines information on the vulnerability traits and abundances of target taxa with estimates of the confidence in data quality (Morato et al, 2018). Quantitative measures of indicator taxa density and spatial extent of associated habitat are viewed as the preferred technique to identify VMEs, but in the deep sea this is rarely possible using data that are independent from fisheries bycatch information (Ardron et al, 2014).…”

“…The best performing models may vary according to the structure of the underlying community and how the data are collected, substantiating the approach of using multiple models and assessing the consistency between them (Norberg et al, 2019). Even where multi-criteria assessments (Morato et al, 2018) take account of abundance in point collections of fauna (e.g., fishery bycatch), there is uncertainty about how well the collections represent faunal density on the seabed because of gear selectivity and differences in the catchability of taxa. In situ photographic image data have the potential to provide abundance data on deep-sea VME taxa when the field-of-view is quantified (Althaus et al, 2009;Clark et al, 2019), and have shown that physical (sled) collections in the deep-sea are prone to underestimate faunal density -possibly by a considerable degree (Williams et al, 2015).…”