Session 16: AES Behavior/Movement & Distribution IRoom: Conference Theater2022-07-29 08:00 - 09:30 |
| Moderator: Chuck Bangley |
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1. 08:00 Does the Electromagnetic Field Noise from Offshore Wind Infrastructure Impact the Behavior, Movement, and Distribution of Elasmobranchs? Kyle Newton*, Oregon State University; Tobey Curtis, NOAA/NEFSC; Taylor Chapple, Oregon State University kylecnewton@yahoo.com
Elasmobranchs use electroreceptors to detect bioelectric field cues of prey during foraging and likely use them to indirectly detect geomagnetic field cues during navigation. Similarly, evidence suggests that some teleosts and decapod crustacean species are magnetically sensitive and use geomagnetic cues for navigation. In an effort to help mitigate the effects of climate change, offshore renewable energy installations are expanding along the U.S. coastline. The high voltage subsea cables of these installations emit electromagnetic field (EMF) noise that can alter the local bioelectric and geomagnetic landscape, which may impair electrically and magnetically mediated behaviors, such as foraging and navigation. Some authors report no effect of EMF on crab distribution in the NE Pacific, whereas, others report that EMF attracts crabs, lobsters, and the Atlantic. To date, the effect of EMF on highly migratory elasmobranchs is unknown. These results highlight the need for comprehensive research on the impact of EMF noise on the sensory physiology and behavioral ecology of EMF sensitive species. Consequently, we have designed a multi-institutional research program that hinges on two broad unifying aims: 1) to develop controlled laboratory validated protocols that quantify the dose dependent behavioral response of EMF sensitive species to EMF noise then, 2) use these data as a model to interpret the behavior of these species as they encounter EMF noise in the field. We aim to integrate these data into habitat and distribution models to understand how EMF noise might alter the critical habitat suitability, movement, and distribution of species near wind farms. |
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2. 08:15 Tracking young bull shark activity in a coastal lagoon with frequent harmful algal blooms. Lauran Brewster*, Florida Atlantic University's Harbor Branch Oceanographic Institute; Michael McCallister, Florida Atlantic University's Harbor Branch Oceanographic Institute; Michelle Edwards, Florida Atlantic University's Harbor Branch Oceanographic Institute; Matthew Ajemian, Florida Atlantic University's Harbor Branch Oceanographic Institute lauran.brewster@gmail.com
The bull shark (Carcharhinus leucas) is a euryhaline elasmobranch that frequents dynamic coastal estuaries. Despite this, there is still little understanding of how sharks respond to fluctuating conditions in these ecosystems, many of which are becoming more variable with coastal development and climate change. Harmful algal blooms (HABs) are one such condition. HABs are a proliferation of algal or cyanobacterial colonies that can detrimentally affect and kill local fauna. Here we report movement and activity data on free-ranging immature bull sharks in the St. Lucie Estuary, Florida, a highly impacted sub-component of the Indian River Lagoon (IRL) with recurring HABs. Sharks were fitted with a custom-built multi-sensor tag package that includes an accelerometer/magnetometer sensor for monitoring body movement/orientation, an acoustic tag for validating positions and a satellite transmitter for recovery. Fifteen tags were deployed over two seasons (wet, dry), and movement documented with collaborative acoustic receiver arrays (i.e., the FACT network). Environmental conditions were monitored by a network of environmental sensors located throughout the IRL. Model results suggest hour of the day, water temperature, depth and cyanobacteria abundance influence activity level but there is substantial individual variation. Space use was variable between individuals. This is an ongoing study that aims to provide the first fine-scale body movement data of immature bull sharks under a) normal conditions and b) in response to HABs in the IRL. This is important as the IRL is a known bull shark nursery and therefore the species is likely integral to its ecosystem structure. |
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3. 08:30 Multi-Year Assessment of Immature Bull Shark Carcharhinus leucas Residency and Activity Spaces in an Expansive Estuarine Nursery. Michelle Edwards*, Harbor Branch Oceanographic Institute, Florida Atlantic University; Michael McCallister, Harbor Branch Oceanographic Institute, Florida Atlantic University; Lauran Brewster, Harbor Branch Oceanographic Institute, Florida Atlantic University; Charles Bangley, Smithsonian Environmental Research Center; Tobey Curtis, Atlantic High Migratory Species Management Division, National Oceanic and Atmospheric Administration; Matthew Ogburn, Smithsonian Environmental Research Center; Matthew Ajemian, Harbor Branch Oceanographic Institute, Florida Atlantic University edwardsm2019@fau.edu
Although portions of Florida’s Indian River Lagoon (IRL) serve as essential fish habitat for U.S. Atlantic coast bull sharks, past studies were short-term (days to months) and encompassed small portions of the expansive estuarine system. In the present study, passive acoustic telemetry was used to track immature bull sharks (n = 29) between Port St. John, Florida and Port Salerno, Florida, and in adjacent shelf waters, up to 4 years (1 January 2017 to 31 December 2020). Dynamic Brownian bridge movement models showed small daily (1.00 km2) and monthly (4.88 km2) core use areas that seasonally shifted (October–March) to include adjacent coastal waters. Tracked bull sharks were found to display residency to the IRL and distinct subregions of the system. Analysis confirmed that bull shark nursery habitat extends 86 km further south than explored by past studies and that adjacent shelf waters are important to immature bull sharks during cooler months each year. This study provides the first multi-year assessment of bull shark space use in a greater expanse of the IRL than previously described. |
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4. 08:45 Recent Occurrence and Movements of Smalltooth Sawfish in the Southern Indian River Lagoon, Florida: Is a Nursery Re-establishing? Andrew K. Wooley*, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Michael P. McCallister, Harbor Branch Oceanographic Institute, Florida Atlantic University; Matthew J. Ajemian, Harbor Branch Oceanographic Institute, Florida Atlantic University; Sara F. Webb, Harbor Branch Oceanographic Institute, Florida Atlantic University; James A. Whittington, Tequesta Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Rachel M. Scharer, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Lukas B. Heath, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Dylan M. Yakich, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Gregg R. Poulakis, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission andrew.wooley@myfwc.com
Historical data show that the Indian River Lagoon (IRL), on Florida’s east coast, once acted as a nursery for the endangered smalltooth sawfish, Pristis pectinata, and supported large numbers of individuals from multiple life stages. However, the species was extirpated from this large estuary by the mid-20th century. In the last several years, the U.S. Sawfish Recovery Hotline (1-844-4SAWFISH; sawfish@MyFWC.com) has received increased numbers of reports from the public in the southern IRL. As a result, 12 sawfish have been tagged by permitted researchers there, including 7 small juveniles. Preliminary acoustic monitoring data show that the small juveniles have been residing in the lower St. Lucie River. This is expected since juveniles typically spend their first few years in occupied, well-established nurseries in southwest Florida. These small juveniles will provide up to 10 years of movement data which will help us determine whether the nursery is re-establishing, characterize the extent of the nursery, and understand habitat use within and beyond the IRL. The two largest juveniles, which have since become adults, moved primarily in the coastal Atlantic Ocean along the entire east coast of Florida from St. Augustine to the Florida Keys, and occasionally moved into western Everglades National Park. Continued reporting by the public, together with ongoing scientific research (e.g., sampling, acoustic monitoring, genetic analyses) will help us learn more about the re-emerging importance of the IRL to the population of smalltooth sawfish found in Florida waters. |