TY - JOUR
T1 - Habitat change mediates the response of coral reef fish populations to terrestrial run-off
AU - Brown, Christopher J.
AU - Jupiter, Stacy D.
AU - Lin, Hsien-Yung
AU - Albert, Simon
AU - Klein, Carissa
AU - Maina, Joseph M.
AU - Tulloch, Vivitskaia J. D.
AU - Wenger, Amelia S.
AU - Mumby, Peter J.
PY - 2017/8/3
Y1 - 2017/8/3
N2 - Coastal fish populations are typically threatened by multiple human activities, including fishing pressure and run-off of terrestrial pollution. Linking multiple threats to their impacts on fish populations is challenging because the threats may influence a species directly, or indirectly, via its habitats and its interactions with other species. Here we examine spatial variation in abundance of coral reef fish across gradients of fishing pressure and turbidity in Fiji. We explicitly account for multiple pathways of influence to test the alternative hypotheses that (1) habitat moderates predation by providing shelter, so habitat loss only affects prey fish populations if there are abundant predators, (2) habitat change co-drives biomass of both prey and predator functional groups. We examined responses of 7 fish functional groups and found that habitat change co-drives both predator and prey responses to turbidity. Abundances of all functional groups were associated with changes in habitat cover; however, the responses of their habitats to turbidity were mixed. Planktivore and piscivore abundance were lower in areas of high turbidity, because cover of their preferred habitats was lower. Invertivore, browser and grazer abundance did not change strongly over the turbidity gradient, because different components of their habitats exhibited both increases and decreases with turbidity. The effects of turbidity on fish populations were minor in areas where fish populations were already depleted by fishing. These findings suggest that terrestrial run-off modifies the composition of reef fish communities indirectly by affecting the benthic habitats that reef fish use.
AB - Coastal fish populations are typically threatened by multiple human activities, including fishing pressure and run-off of terrestrial pollution. Linking multiple threats to their impacts on fish populations is challenging because the threats may influence a species directly, or indirectly, via its habitats and its interactions with other species. Here we examine spatial variation in abundance of coral reef fish across gradients of fishing pressure and turbidity in Fiji. We explicitly account for multiple pathways of influence to test the alternative hypotheses that (1) habitat moderates predation by providing shelter, so habitat loss only affects prey fish populations if there are abundant predators, (2) habitat change co-drives biomass of both prey and predator functional groups. We examined responses of 7 fish functional groups and found that habitat change co-drives both predator and prey responses to turbidity. Abundances of all functional groups were associated with changes in habitat cover; however, the responses of their habitats to turbidity were mixed. Planktivore and piscivore abundance were lower in areas of high turbidity, because cover of their preferred habitats was lower. Invertivore, browser and grazer abundance did not change strongly over the turbidity gradient, because different components of their habitats exhibited both increases and decreases with turbidity. The effects of turbidity on fish populations were minor in areas where fish populations were already depleted by fishing. These findings suggest that terrestrial run-off modifies the composition of reef fish communities indirectly by affecting the benthic habitats that reef fish use.
KW - Coral reef fisheries
KW - Fiji
KW - Integrated coastal management
KW - Land-use change
KW - Trophic-cascade
UR - http://www.scopus.com/inward/record.url?scp=85026869059&partnerID=8YFLogxK
UR - https://ulrichsweb.serialssolutions.com/title/1509329973455/89083
U2 - 10.3354/meps12221
DO - 10.3354/meps12221
M3 - Article
AN - SCOPUS:85026869059
SN - 0171-8630
VL - 576
SP - 55
EP - 68
JO - Marine Ecology Progress Series
JF - Marine Ecology Progress Series
ER -