eCite Digital Repository
Testing CPUE-derived spatial occupancy as an indicator for stock abundance: application to deep-sea stocks
Citation
Trenkel, VM and Beecham, JA and Blanchard, JL and Edwards, CTT and Lorance, P, Testing CPUE-derived spatial occupancy as an indicator for stock abundance: application to deep-sea stocks, Aquatic Living Resources, 26 pp. 319-332. ISSN 0990-7440 (2013) [Refereed Article]
![]() | PDF 882Kb |
Copyright Statement
Copyright 2013 EDP Sciences, IFREMER, IRD
Abstract
The status of an exploited population is ideally determined by monitoring changes in abundance and
distributional range and pattern over time. Area of occupancy is a measure of the current distribution. Unfortunately, for
many populations, scientific abundance and distribution information is not readily available. To evaluate the reliability
of commercial fishing data for deriving occupancy indicators that could serve as proxies for stock abundance, we
investigated four questions: 1) Occupancy changes with stock biomass, but is this change strong enough to make
occupancy a sensitive indicator of population biomass? 2) Fishing boats follow fish, but when does such activity alter
the positive macroecological relationship between occupancy and abundance? 3) When does the activity of pursuing
fish adversely affect occupancy estimates derived from catch and effort data? 4) How does uncertainty in fishing effort
data affect occupancy estimates? Spatial simulations mimicking the dynamics of four deep-water fish species showed
that biomass-occupancy relationships can be weak. Fishers following fish can modify the spatial distribution of target
species, even reversing the sign of the biomass-occupancy relationship in certain cases, and can affect the reliability of
occupancy indicators, which can also be impaired by error in effort data. Using commercial catch and effort data and
abundance indices for deep-sea fish populations to the west of the British Isles it was found that only for roundnose
grenadier might occupancy provide insights into biomass changes. In conclusion, care should be taken when using
occupancy for evaluating range changes in cases where fishing might have modified spatial distributions, uncertain
commercial data are used or when the abundance-occupancy relationship is too flat.
Item Details
Item Type: | Refereed Article |
---|---|
Keywords: | ecosystem indicators, fisheries, deep sea |
Research Division: | Agricultural, Veterinary and Food Sciences |
Research Group: | Fisheries sciences |
Research Field: | Aquaculture and fisheries stock assessment |
Objective Division: | Environmental Management |
Objective Group: | Management of Antarctic and Southern Ocean environments |
Objective Field: | Assessment and management of Antarctic and Southern Ocean ecosystems |
UTAS Author: | Blanchard, JL (Professor Julia Blanchard) |
ID Code: | 100477 |
Year Published: | 2013 |
Web of Science® Times Cited: | 7 |
Deposited By: | Sustainable Marine Research Collaboration |
Deposited On: | 2015-05-18 |
Last Modified: | 2017-11-04 |
Downloads: | 274 View Download Statistics |
Repository Staff Only: item control page