Identifying Fish Nursery Habitats Using Otolith Elemental Fingerprints Completed
Fish otoliths - ear bones - can be used to identify the fish nursery habitat used by estuarine fish.
The Science Issue and Relevance: A priority for sustaining estuarine fisheries is the identification and protection of prime habitat features. However, key questions in estuarine science and management remain about which fish nursery areas actually contribute to adult stocks, and what features characterize “healthy” nursery habitat. This study will determine if elemental fingerprinting in young-of-the-year fish otoliths (ear bones) varies at the scale of individual estuarine tributaries within a large urbanized estuary so that those areas which contribute most prominently to the fishable adult stocks can be identified. Snook (Centropomus undecimalis) and red drum (Sciaenops ocellatus) are economically and ecologically prominent, and have complex life cycles involving movement between open coastal waters and estuarine nursery habitats, including nursery habitats that are located within Tampa Bay’s tidal tributaries. Habitat managers are faced with the question of how to direct strategic efforts to maintain fished populations. Strategic efforts can be made to protect any nursery locations that are found to be disproportionately important in terms of contributing to adult stocks. We hope to identify common factors of those areas that contribute most prominently to habitat quality in nursery habitats.
Methodology for Addressing the Issue: We are using elemental fingerprinting of fish otoliths to determine the degree to which specific estuarine locations contribute to adult fished populations in Tampa Bay. We collected juvenile snook and red drum from selected Tampa Bay tributaries and nearshore locations (Figure 1). We have extracted, sectioned and analyzed the majority of otoliths from these fish (example in Figure 2). We have identified location-specific fingerprints of juvenile snook based on the relative abundance of trace elements. A preliminary finding is that local geologic formation plays a role in the pattern of elements in juvenile snook otoliths (Figure 3). Collection and analysis of adult fish is ongoing. Each adult fish will be assigned to the tributary (or location) used as their nursery habitat based on the elemental fingerprint of the central otolith region (i.e., the region representing the period of growth within nursery habitats). From these results, we will identify the tributaries which are currently contributing most prominently to fishery stocks of these two species in Tampa Bay.
Future Steps: In addition to completing the present analyses, we must determine if identified elemental fingerprint patterns are consistent from year to year (from archived otoliths), as changing land use and hydrographic patterns (e.g. wet vs. dry years) are hypothesized to influence otolith chemical composition. We will then communicate our results to habitat managers, fellow scientists and the public.
Products:
- Ley, JA, CC McIvor, EB Peebles and H Rolls. 2010. Defining Fish Nursery Habitats: An application of otolith elemental fingerprinting in Tampa Bay, Florida, pp 331-346 IN: Cooper, S (Ed), Proceedings, Tampa Bay Area Scientific Information Symposium, BASIS5: 20-23 October 2009, St Petersburg, FL, 538 pp.
- Adam B. Brame, Carole C. McIvor, Ernst B. Peebles, David J. Hollander. 2014. Site fidelity and condition metrics suggest sequential habitat use by early juvenile snook. Marine Ecology Progress Series 509: 255-269.
- Krebs, Justin M., Bell, Susan S., McIvor, Carole C. 2014. Assessing the link between coastal urbanization and the quality of nekton habitat in mangrove tidal tributaries. Estuaries and Coasts, 37: 832-846.
- Krebs, Justin M., McIvor, Carole C., Bell, Susan S. 2014. Nekton community structure varies in response to coastal urbanization near mangrove tidal tributaries. Estuaries and Coasts, 37: 815-831.
Fish otoliths - ear bones - can be used to identify the fish nursery habitat used by estuarine fish.
The Science Issue and Relevance: A priority for sustaining estuarine fisheries is the identification and protection of prime habitat features. However, key questions in estuarine science and management remain about which fish nursery areas actually contribute to adult stocks, and what features characterize “healthy” nursery habitat. This study will determine if elemental fingerprinting in young-of-the-year fish otoliths (ear bones) varies at the scale of individual estuarine tributaries within a large urbanized estuary so that those areas which contribute most prominently to the fishable adult stocks can be identified. Snook (Centropomus undecimalis) and red drum (Sciaenops ocellatus) are economically and ecologically prominent, and have complex life cycles involving movement between open coastal waters and estuarine nursery habitats, including nursery habitats that are located within Tampa Bay’s tidal tributaries. Habitat managers are faced with the question of how to direct strategic efforts to maintain fished populations. Strategic efforts can be made to protect any nursery locations that are found to be disproportionately important in terms of contributing to adult stocks. We hope to identify common factors of those areas that contribute most prominently to habitat quality in nursery habitats.
Methodology for Addressing the Issue: We are using elemental fingerprinting of fish otoliths to determine the degree to which specific estuarine locations contribute to adult fished populations in Tampa Bay. We collected juvenile snook and red drum from selected Tampa Bay tributaries and nearshore locations (Figure 1). We have extracted, sectioned and analyzed the majority of otoliths from these fish (example in Figure 2). We have identified location-specific fingerprints of juvenile snook based on the relative abundance of trace elements. A preliminary finding is that local geologic formation plays a role in the pattern of elements in juvenile snook otoliths (Figure 3). Collection and analysis of adult fish is ongoing. Each adult fish will be assigned to the tributary (or location) used as their nursery habitat based on the elemental fingerprint of the central otolith region (i.e., the region representing the period of growth within nursery habitats). From these results, we will identify the tributaries which are currently contributing most prominently to fishery stocks of these two species in Tampa Bay.
Future Steps: In addition to completing the present analyses, we must determine if identified elemental fingerprint patterns are consistent from year to year (from archived otoliths), as changing land use and hydrographic patterns (e.g. wet vs. dry years) are hypothesized to influence otolith chemical composition. We will then communicate our results to habitat managers, fellow scientists and the public.
Products:
- Ley, JA, CC McIvor, EB Peebles and H Rolls. 2010. Defining Fish Nursery Habitats: An application of otolith elemental fingerprinting in Tampa Bay, Florida, pp 331-346 IN: Cooper, S (Ed), Proceedings, Tampa Bay Area Scientific Information Symposium, BASIS5: 20-23 October 2009, St Petersburg, FL, 538 pp.
- Adam B. Brame, Carole C. McIvor, Ernst B. Peebles, David J. Hollander. 2014. Site fidelity and condition metrics suggest sequential habitat use by early juvenile snook. Marine Ecology Progress Series 509: 255-269.
- Krebs, Justin M., Bell, Susan S., McIvor, Carole C. 2014. Assessing the link between coastal urbanization and the quality of nekton habitat in mangrove tidal tributaries. Estuaries and Coasts, 37: 832-846.
- Krebs, Justin M., McIvor, Carole C., Bell, Susan S. 2014. Nekton community structure varies in response to coastal urbanization near mangrove tidal tributaries. Estuaries and Coasts, 37: 815-831.