Combined Abundance of All Vulnerable Marine Ecosystem Indicator Taxa Inadequate as Sole Determiner of Vulnerability, Antarctic Peninsula

Susanne J. Lockhart,John Hocevar

doi:10.3389/fmars.2021.577761

Abstract

In order to achieve conservation objectives and preserve the biodiversity of the Southern Ocean, a variety of ecosystems must be protected. This holds especially true for the benthic communities of this region that are characteristically mosaic in their spatial distributions. As such, disparate communities cannot be comprehensively assessed by a single blanket methodology. Herein, evidence appropriate to the diverse characteristics of the communities encountered during a submarine expedition demonstrates the particular vulnerability of four sites that exemplify VMEs as defined by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the UN’s Fisheries and Agriculture Organization (FAO). Three sites are identified as VMEs based on highly significant abundances of indicator taxa. A fourth is identified based on a high density of cold-water coral taxa, many of which were not observed in abundance at the sites that were triggered as vulnerable by a significantly high abundance of all indicator taxa. The VME at this latter site was richly diverse in coral taxa, many of which are considered particularly vulnerable to climate change, as well as critical for their potential for genuine blue carbon sequestration. As of November, 2018, all four sites are now registered with CCAMLR as VMEs and thus, are afforded protection from all bottom fishing activities. However, if consideration isn’t given to the composition and/or diversity of VME indicator taxa present, in addition to overall abundance/density, some of the most vulnerable communities are left at risk. A blanket threshold for all VME taxa adhered to in fisheries management of the Southern Ocean, and other high seas areas, is grossly insufficient. Without taking a more precautionary approach to identifying and protecting VMEs, CCAMLR will not be able to meet its conservation objectives and may even be putting Antarctic fisheries at risk.

Highlights

Identification of Vulnerable Marine Ecosystems (VMEs) is a critical component of the management framework for bottom fishing activities
The relevance of VMEs in the Southern Ocean has never been greater as the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR)—the international body tasked with managing commercial fishing operations around Antarctica—pursues their 2004 commitment to establish a network of Marine Protected Areas (MPAs) throughout the Southern Ocean (Conservation Measure 91–04; CCAMLR, 2019b)
Bare substrate at Dive sites 1, 3, and 5 (Hope Bay, Kinnes Cove and Trinity Is, respectively), was not common (Figures 5–7), except where an ice scour zone was crossed during Dive 1 (Figure 5B). The communities at these sites clearly exhibit the high density of VME indicator taxa, as well as the complex three-dimensional structure expected of a typical VME

Summary

Introduction

Identification of Vulnerable Marine Ecosystems (VMEs) is a critical component of the management framework for bottom fishing activities. This was brought about largely by the requirements of United Nations General Assembly (UNGA) Sustainable Fisheries Resolution (61/105), aimed at avoiding significant adverse impacts of bottom fishing activities on VMEs in high seas areas (UNGA, 2007). The urgency for protection of this region is underscored by the increased rate of warming that the Peninsula has experienced (Turner et al, 2005, 2016; Jones et al, 2019; Siegert et al, 2019), at a time when industrialized krill fishing along the Antarctic Peninsula is expanding and pressures continue to mount for expansion of commercial benthic long-line fisheries. Fundamental to vulnerability is resilience and recovery from damage is considered to be extremely slow, or will not occur, if species are rare, unique or exhibit high levels of endemism, or, possess life-history or biological characteristics that include slow growth rates, high longevity, large age of maturity or low recruitment (Rogers et al, 2008)

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