Priorities for synthesis research in ecology and environmental science

ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD

Priorities for synthesis research in ecology and environmental science

ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD

Separation Anxiety: Mussels Self-Organize into Similar Power-Law Clusters Regardless of Predation Threat Cues

Mussels have myriad effects on population, community, and ecosystem processes. Their aggregation behavior is an inducible defense that links non-consumptive effects of predators to benthic spatial pattern formation. Aggregation increases intraspecific competition but can be beneficial due to lower perimeter-related predation and other risks. Mytilus edulis aggregation responses to predation threats have not been investigated outside of Europe. We studied the effects of chemical cues from heterospecifics (predators Carcinus maenas, Nucella lapillus; herbivore Littorina littorea) and conspecifics (injured and intact M. edulis) on M. edulis aggregation behavior in Maine, USA. Mussels self-organized into fractal power-law spatial patterns like those in the field. Aggregations had lower perimeter:area (P:A) ratios than singletons, despite having more complex, irregular shapes with higher fractal dimensions (D). However, with one exception, no significant differences in aggregation rate, P:A ratio, and D were observed for any chemical cue treatment when compared to no-cue controls. Our experiment revealed higher aggregation rates than reported from similar experiments, leaving little scope for additional aggregation when exposed to chemical cues. We suggest that increased aggregation in response to predation threat is context-dependent: costs outweigh benefits beyond some optimal aggregation size, and mussels in our experiment were at the upper aggregation limit beyond which more aggregation could have negative consequences. Bet-hedging with a power-law distribution of aggregation shapes and sizes may be the optimal spatial strategy, especially if predation and other risks are variable in space and time

Implantation and Recovery of Long-Term Archival Transceivers in a Migratory Shark with High Site Fidelity

Publisher's PDF.We developed a long-term tagging method that can be used to understand species assemblages and social groupings associated with large marine fishes such as the Sand Tiger shark Carcharias taurus.We deployed internally implanted archival VEMCO Mobile Transceivers (VMTs; VEMCO Ltd. Nova Scotia, Canada) in 20 adult Sand Tigers, of which two tags were successfully recovered (10%). The recovered VMTs recorded 29,646 and 44,210 detections of telemetered animals respectively. To our knowledge, this is the first study to demonstrate a method for long-term (~ 1 year) archival acoustic transceiver tag implantation, retention, and recovery in a highly migratory marine fish. Results show low presumed mortality (n = 1, 5%), high VMT retention, and that non-lethal recovery after almost a year at liberty can be achieved for archival acoustic transceivers. This method can be applied to study the social interactions and behavioral ecology of large marine fishes.University of Delaware. College of Earth, Ocean, and Environment

Tagging and recapture information for adult Sand Tigers <i>Carcharias taurus</i> implanted with VEMCO Mobile Transceivers (VMTs).

<p>Tagging and recapture information for adult Sand Tigers <i>Carcharias taurus</i> implanted with VEMCO Mobile Transceivers (VMTs).</p

VEMCO Mobile Transceiver (VMT) insertion procedure.

<p>a) Location of the ~5cm incision made just off the midline on the ventral side of the animal. The incision went through the body wall and into the peritoneal cavity. Adapted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0148617#pone.0148617.ref028" target="_blank">28</a>]. b) Martin Uterine ½ circle reverse cutting needle (size 6) inserted through the serosal surface of the peritoneal cavity, but not protruding through the skin. The non-absorbable nylon monofilament was twice looped through this tissue. c) Example of the surgical knots that were tied to secure the 4 loose ends of nylon monofilament looped through the serosal surface of the peritoneal cavity. Four surgical knots were tied with the two pairs of loose ends and ends were trimmed.</p

Social Network Analysis Reveals Potential Fission-Fusion Behavior in a Shark

Publisher's PDFComplex social networks and behaviors are difficult to observe for free-living marine species, especially those that move great distances. Using implanted acoustic transceivers to study the inter-and intraspecific interactions of sand tiger sharks Carcharias taurus, we observed group behavior that has historically been associated with higher order mammals. We found evidence strongly suggestive of fission-fusion behavior, or changes in group size and composition of sand tigers, related to five behavioral modes (summering, south migration, community bottleneck, dispersal, north migration). Our study shows sexually dimorphic behavior during migration, in addition to presenting evidence of a potential solitary phase for these typically gregarious sharks. Sand tigers spent up to 95 consecutive and 335 cumulative hours together, with the strongest relationships occurring between males. Species that exhibit fission-fusion group dynamics pose a particularly challenging issue for conservation and management because changes in group size and composition affect population estimates and amplify anthropogenic impacts.University of Delware, College of Earth, Ocean, and Environmen

Presence and absence of telemetered sharks.

<p>Detections of 20 adult Sand Tigers <i>Carcharias taurus</i> outfitted with VEMCO Mobile Transceivers (VMTs) on VEMCO VR-2W moored acoustic receivers located in the Delaware Bay, Delaware USA, the surrounding coastal ocean, and outside receiver arrays along the East Coast United States part of the Atlantic Cooperative Telemetry Network (ACT). All sharks were detected one or two years after surgery except Shark 1.</p

The healed scar from initial tag implantation.

<p>The surgical scar was just off the midline of Shark 14 when it was recaptured and the implanted VEMCO Mobile Transceiver (VMT) was recovered. The shark had been at liberty for 352 days after initial tagging. The shark was tagged and recaptured in the Delaware Bay, Delaware USA.</p

Tag attachment setup.

<p>Non-absorbable 18kg nylon monofilament was threaded through the Martin Uterine ½ circle reverse cutting needle (size 6), and attached to the VEMCO Mobile Transceivers (VMTs) by threading the monofilament through a factory-drilled hole on the VMTs. The ends were tied using four surgical knots.</p