Continental-scale models of pelagic fish hotspots: Can geoscience guide the conservation of mobile oceanic predators?  

Authors / CoAuthors

Huang, Z. | Nichol, S.L.

Abstract

This study demonstrates that seabed topography and geodiversity play key roles in controlling the spatial dynamics of large fish predators over macro-ecological scales. We compiled ten years of commercial fishing records from the Sea Around Us Project and developed continental-scale catch models for an assemblage of large open-water fish (e.g. tuna, marlins, mackerels) for Western Australia. We standardised catch rates to account for the confounding effects of year, gear type and species body mass using generalised linear models, from which relative indices of abundance were extracted. We combined these with an extensive array of geophysical, oceanographic, biological, and anthropogenic data to (1) map the location of pelagic hotspots and (2) determine their most likely mechanistic drivers. We tested whether submarine canyons promote the aggregation of pelagic fish, and whether geomorphometrics (measures of seafloor complexity) represent useful surrogate indicators of their numbers. We also compared predicted fish distributions with the Australian network of Commonwealth Marine Reserves to assess its potential to provide conservation benefits for highly mobile predators. Both static and dynamic habitat features explained the observed patterns in relative abundance of pelagic fish. Geomorphometrics alone captured more than 50% of the variance, and submarine canyon presence ranked as the most influential variable in the North bioregion. Seafloor rugosity and fractal dimension, salinity, ocean energy, current strength, and human use were also identified as important predictors. The spatial overlap between fish hotspots and marine reserves was very limited in most parts of the EEZ, with high-abundance areas being primarily found in multiple use zones where human activities are subject to few restrictions.

Product Type

nonGeographicDataset

eCat Id

82135

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Keywords

• External PublicationScientific Journal Paper

( Theme )

• marine biodiversity

( Theme )

• NERP Marine Biodiversity Hub

( Theme )

• seabed

( Theme )

• marine park

( Theme )

• marine

( Theme )

• NERP

• WA

Australian and New Zealand Standard Research Classification (ANZSRC)

• Marine Geoscience

• Published_Internal

Publication Date

2014-09-09T00:00:00

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Australian Government Security ClassificationSystem    

Classification - unclassified

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Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

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Purpose

Maintenance Information

notPlanned

Topic Category

oceans

Series Information

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Unknown

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Reference System

Spatial Resolution

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