Patterns of resource use and isotopic niche overlap among three species of sharks occurring within a protected subtropical estuary

Austin J. Gallagher, David S. Shiffman, Evan E. Byrnes, C. M. Hammerschlag-Peyer, Neil Hammerschlag

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Predation is one of the most fundamental and unifying concepts in ecology, and we are beginning to obtain a more complete understanding of how predators drive community structure and ecosystem function through their impacts on prey. We know considerably less about how predators affect each other through intraguild interactions, which is surprising considering predators often occur simultaneously and may compete for resources while avoiding being killed themselves. In the present study, we examined aspects of inter- and intra-specific resource use among three species of large-bodied predatory sharks (blacktip, bull, lemon) co-occurring within a subtropical, protected bay in the southeastern USA. Specifically, we inferred relative trophic position, isotopic niche overlap, and patterns of resource use of sharks using stable isotope analysis of carbon-13 and nitrogen-15 from blood and fin cartilage samples. We also combined these approaches with estimates of abundance and occurrence from empirical shark surveys to consider whether these species may exhibit resource partitioning in space and time. We found that all three species overlapped in space, and there was some isotopic niche overlap between the species. We also found evidence of temporal isotopic niche stability, suggesting that co-occurring shark species may compete for available prey resources, but individuals of those species may have similar patterns of resource use over time. We discuss our findings as they relate to the ecologies of the species in question and how sound conservation and management of ecosystems can allow for predator diversity, sympatry, and stable use of resources at the top of the food chain.

Original languageEnglish (US)
Pages (from-to)1-14
Number of pages14
JournalAquatic Ecology
DOIs
StateAccepted/In press - May 19 2017

Fingerprint

niche overlap
shark
sharks
resource use
niches
estuaries
estuary
predators
predator
Carcharhinus limbatus
ecology
ecosystem management
lemons
food chain
sympatry
cartilage
space and time
intraguild interaction
fins
stable isotopes

Keywords

  • Feeding
  • Intraguild
  • Partitioning
  • Predation risk
  • Predator
  • Shark

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science

Cite this

Patterns of resource use and isotopic niche overlap among three species of sharks occurring within a protected subtropical estuary. / Gallagher, Austin J.; Shiffman, David S.; Byrnes, Evan E.; Hammerschlag-Peyer, C. M.; Hammerschlag, Neil.

In: Aquatic Ecology, 19.05.2017, p. 1-14.

Research output: Contribution to journalArticle

Gallagher, Austin J. ; Shiffman, David S. ; Byrnes, Evan E. ; Hammerschlag-Peyer, C. M. ; Hammerschlag, Neil. / Patterns of resource use and isotopic niche overlap among three species of sharks occurring within a protected subtropical estuary. In: Aquatic Ecology. 2017 ; pp. 1-14.
@article{fce92015524c4935b2e84f97d75aed9a,
title = "Patterns of resource use and isotopic niche overlap among three species of sharks occurring within a protected subtropical estuary",
abstract = "Predation is one of the most fundamental and unifying concepts in ecology, and we are beginning to obtain a more complete understanding of how predators drive community structure and ecosystem function through their impacts on prey. We know considerably less about how predators affect each other through intraguild interactions, which is surprising considering predators often occur simultaneously and may compete for resources while avoiding being killed themselves. In the present study, we examined aspects of inter- and intra-specific resource use among three species of large-bodied predatory sharks (blacktip, bull, lemon) co-occurring within a subtropical, protected bay in the southeastern USA. Specifically, we inferred relative trophic position, isotopic niche overlap, and patterns of resource use of sharks using stable isotope analysis of carbon-13 and nitrogen-15 from blood and fin cartilage samples. We also combined these approaches with estimates of abundance and occurrence from empirical shark surveys to consider whether these species may exhibit resource partitioning in space and time. We found that all three species overlapped in space, and there was some isotopic niche overlap between the species. We also found evidence of temporal isotopic niche stability, suggesting that co-occurring shark species may compete for available prey resources, but individuals of those species may have similar patterns of resource use over time. We discuss our findings as they relate to the ecologies of the species in question and how sound conservation and management of ecosystems can allow for predator diversity, sympatry, and stable use of resources at the top of the food chain.",
keywords = "Feeding, Intraguild, Partitioning, Predation risk, Predator, Shark",
author = "Gallagher, {Austin J.} and Shiffman, {David S.} and Byrnes, {Evan E.} and Hammerschlag-Peyer, {C. M.} and Neil Hammerschlag",
year = "2017",
month = "5",
day = "19",
doi = "10.1007/s10452-017-9627-2",
language = "English (US)",
pages = "1--14",
journal = "Netherlands Journal of Aquatic Ecology",
issn = "1380-8427",
publisher = "Springer Netherlands",

}

TY - JOUR

T1 - Patterns of resource use and isotopic niche overlap among three species of sharks occurring within a protected subtropical estuary

AU - Gallagher, Austin J.

AU - Shiffman, David S.

AU - Byrnes, Evan E.

AU - Hammerschlag-Peyer, C. M.

AU - Hammerschlag, Neil

PY - 2017/5/19

Y1 - 2017/5/19

N2 - Predation is one of the most fundamental and unifying concepts in ecology, and we are beginning to obtain a more complete understanding of how predators drive community structure and ecosystem function through their impacts on prey. We know considerably less about how predators affect each other through intraguild interactions, which is surprising considering predators often occur simultaneously and may compete for resources while avoiding being killed themselves. In the present study, we examined aspects of inter- and intra-specific resource use among three species of large-bodied predatory sharks (blacktip, bull, lemon) co-occurring within a subtropical, protected bay in the southeastern USA. Specifically, we inferred relative trophic position, isotopic niche overlap, and patterns of resource use of sharks using stable isotope analysis of carbon-13 and nitrogen-15 from blood and fin cartilage samples. We also combined these approaches with estimates of abundance and occurrence from empirical shark surveys to consider whether these species may exhibit resource partitioning in space and time. We found that all three species overlapped in space, and there was some isotopic niche overlap between the species. We also found evidence of temporal isotopic niche stability, suggesting that co-occurring shark species may compete for available prey resources, but individuals of those species may have similar patterns of resource use over time. We discuss our findings as they relate to the ecologies of the species in question and how sound conservation and management of ecosystems can allow for predator diversity, sympatry, and stable use of resources at the top of the food chain.

AB - Predation is one of the most fundamental and unifying concepts in ecology, and we are beginning to obtain a more complete understanding of how predators drive community structure and ecosystem function through their impacts on prey. We know considerably less about how predators affect each other through intraguild interactions, which is surprising considering predators often occur simultaneously and may compete for resources while avoiding being killed themselves. In the present study, we examined aspects of inter- and intra-specific resource use among three species of large-bodied predatory sharks (blacktip, bull, lemon) co-occurring within a subtropical, protected bay in the southeastern USA. Specifically, we inferred relative trophic position, isotopic niche overlap, and patterns of resource use of sharks using stable isotope analysis of carbon-13 and nitrogen-15 from blood and fin cartilage samples. We also combined these approaches with estimates of abundance and occurrence from empirical shark surveys to consider whether these species may exhibit resource partitioning in space and time. We found that all three species overlapped in space, and there was some isotopic niche overlap between the species. We also found evidence of temporal isotopic niche stability, suggesting that co-occurring shark species may compete for available prey resources, but individuals of those species may have similar patterns of resource use over time. We discuss our findings as they relate to the ecologies of the species in question and how sound conservation and management of ecosystems can allow for predator diversity, sympatry, and stable use of resources at the top of the food chain.

KW - Feeding

KW - Intraguild

KW - Partitioning

KW - Predation risk

KW - Predator

KW - Shark

UR - http://www.scopus.com/inward/record.url?scp=85019575128&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85019575128&partnerID=8YFLogxK

U2 - 10.1007/s10452-017-9627-2

DO - 10.1007/s10452-017-9627-2

M3 - Article

AN - SCOPUS:85019575128

SP - 1

EP - 14

JO - Netherlands Journal of Aquatic Ecology

JF - Netherlands Journal of Aquatic Ecology

SN - 1380-8427

ER -