Vulnerable, but Still Poorly Known, Marine Ecosystems: How to Make Distribution Models More Relevant and Impactful for Conservation and Management of VMEs?

Abstract

Human activity puts our oceans under multiple stresses, whose impacts are already significantly affecting biodiversity and physicochemical properties. Consequently, there is an increased international focus on the conservation and sustainable use of oceans, including the protection of fragile benthic biodiversity hotspots in the deep sea, identified as vulnerable marine ecosystems (VMEs). International VME risk assessment and conservation efforts are hampered because we largely do not know where VMEs are located. VME distribution modelling has increasingly been recommended to extend our knowledge beyond sparse observations. Nevertheless, the adoption of VME distribution models in spatial management planning and conservation remains limited. This work critically reviews VME distribution modelling studies, and recommends promising avenues to make VME models more relevant and impactful for policy and management decision making. First, there is an important interplay between the type of VME data used to build models and how the generated maps can be used in making management decisions, which is often ignored by model-builders. Overall, there is a need for more precise VME data for production of reliable models. We provide specific guidelines for seven common applications of VME distribution modelling to improve the matching between the modelling and the user need. Second, the current criteria to identify VME often rely on subjective thresholds, which limits the transparency, transferability and effective applicability of distribution models in protection measures. We encourage scientists towards founding their models on: (i) specific and quantitative definitions of what constitute a VME, (ii) site conservation value assessment in relation to VME multi-taxon spatial predictions, and (iii) explicitly mapping vulnerability. Along with the recent increase in both deep-sea biological and environmental data quality and quantity, these modelling recommendations can lead towards more cohesive summaries of VME’s spatial distributions and their relative vulnerability, which should facilitate a more effective protection of these ecosystems, as has been mandated by numerous international agreements.

Evaluation of the full set of habitat suitability models for vulnerable marine ecosystem indicator taxa in the South Pacific high seas

“…While this study was based in the South Pacific high seas, New Zealand, and Australia, the results also have implications for modelling efforts aiming to conserve biodiversity beyond national jurisdictions elsewhere. Future efforts must strive for spatial datasets of abundance, as only they can provide the information needed to identify and test VME density thresholds and thereby enable more effective spatial management of extractive activities such as fishing (Gros et al., 2022).…”

Using joint species distribution modelling to predict distributions of seafloor taxa and identify vulnerable marine ecosystems in New Zealand waters

“…We also, for the rst time, explore how these abundance data can be directly related to one or more of the FAO (2009) functional de nitions of a VME (e.g., as implemented by Gros et al, 2023) to highlight important areas which are most likely to contain VMEs and may be at most risk from the impact of bottom trawling. Information of this nature is of critical importance for effective spatial management that aims to prevent or mitigate signi cant adverse impacts to VMEs (Gros et al, 2022).…”

“…These data provide the opportunity to generate spatial estimates of taxon abundances (rather than simply occurrences) and, in this case, to also test the use of JSDMs which may better account for species-interactions and more easily incorporate rarer species in a quantitative manner (Zhang et al, 2020a). Furthermore, outputs from JDSMs can be used to predict the occurrence of ecosystems represented by a composite of species (Ovaskainen et al, 2017), including Vulnerable Marine Ecosystems (VMEs) (Gros et al, 2022).…”

Remote sensing of Antarctic polychaete reefs (Serpula narconensis): reproducible workflows for quantifying benthic structural complexity with action cameras, remotely operated vehicles and structure‐from‐motion photogrammetry

“…Nonetheless, within the Southern Ocean, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) has committed to avoid significant adverse impacts to VMEs (CCAMLR, 2009). Yet, there is poor knowledge of the location and ecology of VMEs around Antarctica (Chown & Brooks, 2019; Gros et al., 2022). Furthermore, biogenic structures around Antarctica are considered particularly sensitive to climate change, as many have carbonate frameworks that could weaken or dissolve in response to accelerated ocean acidification in the extremely cold waters (Brasier et al., 2021; Figuerola et al., 2021; Hancock et al., 2020).…”