Michael W. Feeley | USGS Science

USGS2012

Home range, habitat use, and migrations of hawksbill turtles tracked from Dry Tortugas National Park, Florida, USA

To determine habitat-use patterns of sub-adult hawksbills Eretmochelys imbricata , we conducted satellite- and acoustic-tracking of 3 turtles captured in August 2008 within Dry Tortugas National Park (DRTO), south Florida, USA, in the Gulf of Mexico; turtles ranged in size from 51.9 to 69.8 cm straight carapace length. After 263, 699, and 655 d of residence in the park, turtles migrated out of the DRTO. Within the park, core-use areas (i.e. 50% kernel density estimates) were 9.2 to 21.5 km 2 ; all 3 turtle core-use areas overlapped in an area 6.1 km 2 within a zone of the park with multiple human uses (e.g. fishing, anchoring). Two turtles migrated to Cuba and ceased transmitting after 320 and 687 tracking days; the third turtle migrated toward Key West, Florida, and ceased transmitting after 884 tracking days. The present study highlights previously unknown regional connections for hawksbills, possible turtle-harvest incidents, and fine-scale habitat use of sub-adult hawksbills within a United States National Park.

Florida↗

USGS2012

Rapid invasion of the Indo-Pacific lionfishes (Pterois volitans and Pterois miles) in the Florida Keys, USA: evidence from multiple pre-and post-invasion data sets

Over the past decade, Indo-Pacific lionfishes, Pterois volitans (Linnaeus, 1758) and Pterois miles (Bennett, 1828), venomous members of the scorpionfish family (Scorpaenidae), have invaded and spread throughout much of the tropical and subtropical northwestern Atlantic Ocean and Caribbean Sea. These species are generalist predators of fishes and invertebrates with the potential to disrupt the ecology of the invaded range. Lionfishes have been present in low numbers along the east coast of Florida since the 1980s, but were not reported in the Florida Keys until 2009. We document the appearance and rapid spread of lionfishes in the Florida Keys using multiple long-term data sets that include both pre- and post-invasion sampling. Our results are the first to quantify the invasion of lionfishes in a new area using multiple independent, ongoing monitoring data sets, two of which have explicit estimates of sampling effort. Between 2009 and 2011, lionfish frequency of occurrence, abundance, and biomass increased rapidly, increasing three- to six-fold between 2010 and 2011 alone. In addition, individuals were detected on a variety of reef and non-reef habitats throughout the Florida Keys. Because lionfish occurrence, abundance, and impacts are expected to continue to increase throughout the region, monitoring programs like those used in this study will be essential to document ecosystem changes that may result from this invasion.

Floria Keys↗