Ecological indicators to capture the effects of fishing on biodiversity and conservation status of marine ecosystems

Abstract

This document is a U.S. government work and is not subject to copyright in the United States. IndiSeas ("Indicators for the Seas") is a collaborative international working group that was established in 2005 to evaluate the status of exploited marine ecosystems using a suite of indicators in a comparative framework. An initial shortlist of seven ecological indicators was selected to quantify the effects of fishing on the broader ecosystem using several criteria (i.e., ecological meaning, sensitivity to fishing, data availability, management objectives and public awareness). The suite comprised: (i) the inverse coefficient of variation of total biomass of surveyed species, (ii) mean fish length in the surveyed community, (iii) mean maximum life span of surveyed fish species, (iv) proportion of predatory fish in the surveyed community, (v) proportion of under and moderately exploited stocks, (vi) total biomass of surveyed species, and (vii) mean trophic level of the landed catch. In line with the Nagoya Strategic Plan of the Convention on Biological Diversity (2011-2020), we extended this suite to emphasize the broader biodiversity and conservation risks in exploited marine ecosystems. We selected a subset of indicators from a list of empirically based candidate biodiversity indicators initially established based on ecological significance to complement the original IndiSeas indicators. The additional selected indicators were: (viii) mean intrinsic vulnerability index of the fish landed catch, (ix) proportion of non-declining exploited species in the surveyed community, (x) catch-based marine trophic index, and (xi) mean trophic level of the surveyed community. Despite the lack of data in some ecosystems, we also selected (xii) mean trophic level of the modelled community, and (xiii) proportion of discards in the fishery as extra indicators. These additional indicators were examined, along with the initial set of IndiSeas ecological indicators, to evaluate whether adding new biodiversity indicators provided useful additional information to refine our understanding of the status evaluation of 29 exploited marine ecosystems. We used state and trend analyses, and we performed correlation, redundancy and multivariate tests. Existing developments in ecosystembased fisheries management have largely focused on exploited species. Our study, using mostly fisheries independent survey-based indicators, highlights that biodiversity and conservation-based indicators are complementary to ecological indicators of fishing pressure. Thus, they should be used to provide additional information to evaluate the overall impact of fishing on exploited marine ecosystems.

Indicator-Based Assessment of Marine Biological Diversity–Lessons from 10 Case Studies across the European Seas

“…Results from the Norwegian part of the Barents sea indicated a general good status, which is in accordance with indicators of fish status on exploited large marine ecosystems (Kleisner et al, 2014;Coll et al, 2015), the report on the Barents Sea management plan (Sunnana et al, 2010) and the work from Certain et al (2011). Nevertheless, several indicators indicated potentially degraded situations both in the coastal area and in the area of seasonal ice presence: (1) Along northern Norway coast, the current extent of kelp forest, an important component of fjords ecosystem and coastal landscape, cannot be considered as good in northern Norway.…”

What Is Marine Biodiversity? Towards Common Concepts and Their Implications for Assessing Biodiversity Status

“…Where the aim of assessment is toward sustainable management, such as in the MSFD, or marine conservation, the selected food-web measurement parameters and indicators must focus on detecting the impacts of anthropogenic pressures (Coll et al, 2016). However, for a programme to understand the overall predator-prey structure in a system, all levels of interactions should be included into the underlying view on the biodiversity as the basis of the assessment.…”

Biodiversity and Abundance of Demersal Fishs Stock in Tambelan Water, Natuna Sea

“…Peran sebagai nursery ground (ecosystem services) dapat mengendalikan keseimbangan biodiversitas di suatu perairan (Liquete et al, 2016). Walaupun keragaman dapat terjadi karena pengaruh penangkapan maupun karena indikator ekologi lainya yang saling terkait (Coll et al, 2016) dan landskap ekologi ekosistem (Ives et al, 2015). Rencana penerapan kawasan konservasi berdasarkan indikator penangkapan karena dapat berdampak global (Castello and Bantine, 2015).…”