Data Management Plan (Deprecated)

Coastal shark community structure was quantified across 10 geographic areas in the northeastern Gulf of Mexico using fishery-independent gillnet data from 2003-2011. A total of 3,205 sets were made in which 14,244 carcharhiniform sharks, primarily juveniles, were caught comprising 11 species from three families. Atlantic sharpnose sharks (Rhizoprionodon terraenovae) were the most abundant species overall followed by bonnethead (Sphyrna tiburo) and blacktip sharks (Carcharhinus limbatus). Two-way crossed analysis of similarity (ANOSIM) found geographic area to significantly influence shark species-life stage assemblages while season did not. Resemblance matrices between environmental data and shark community assemblage found the two were significantly correlated with the combination of salinity and turbidity producing the highest spearman rank correlation value. Species diversity varied by geographic area, but was generally highest in areas with the greatest amount of fresh and saltwater fluctuations. The mean size of the three most abundant species differed across geographic areas whereas, those species in lower abundances also differed across regions, but exhibited no discernible pattern. Our results suggest geographic area is important for juvenile sharks and some areas may be considered important nursery areas for many species. Atlantic sharpnose and blacktip shark were not restricted to any specific geographic area but species such as bull (C. leucas), spinner (C. brevipinna), blacknose (C. acronotus), finetooth (C. isodon), sandbar (C. plumbeus) and scalloped hammerhead (S. lewini) sharks were only consistently captured within a single area or over a select group of areas.

Gulf Of Mexico

Process Steps:

• Methods Gear and set specifications The survey was modeled after methods developed by Carlson and Brusher (1999). A monofilament gillnet consisting of six different stretched-mesh size panels was used for sampling in all areas by all institutions. Stretched-mesh sizes ranged from 7.6 (3.0) to 14.0 cm (5.5) in steps of 1.3 cm (0.5). Each panel was 3.0 m (10 ft) deep and 30.5 m (100 ft) long. Panel specifics can be found in Baremore et al. (2012). The six panels were strung together and fished as a single gear (i.e., set). The survey was conducted monthly April October in coastal bays, estuaries, and around barrier islands (out to three nautical miles) from 2003 to 2011, covering more than 550 km of coastline (Fig. 1). Gillnet sets were chosen randomly and the gear was fished either perpendicular to shore or with the wind. Set soak time was defined from the time the gear entered the water to the time the gear was removed completely from the water. Haul back typically started 0.51.0 h after the gear first entered the water. After haul back, the gear was moved to a different location, beginning a new set. All gillnet sets were made during daylight hours (07:0018:00). For each set, mid-water temperature (C), salinity, and dissolved oxygen (mg l-1 ) were recorded. Average depth (m) was calculated using gear start and end points recorded from the vessels depth finder, and water clarity (depth of the photic zone, cm) was measured by secchi disc. At times, not all environmental parameters were recorded due to logistics. Not all institutions sampled in all years due to funding. The two longest running data sets were from the NOAA National Marine Fisheries Service Panama City Laboratory (St. Andrew Bay to Apalachicola Bay, FL 20032011) and University of Southern Mississippi Gulf Coast Research Laboratory (Mississippi Sound and sets made outside the Mississippi barrier islands 20032009). The remaining datasets were: the Florida Museum of Natural History at the University of Florida (Suwannee Sound to Waccasassa Bay, FL 20072011), the Dauphin Island Sea Laboratory (Mobile Bay and Alabama and sets around western Florida barrier islands 20072011), and the Florida State University Coastal and Marine Laboratory (St. George Sound to Anclote Key, FL 20082011). 1234 Environ Biol Fish (2015) 98:12331254

Findings from this dataset are published in a peer-reviewed journal. This is a static data set that has undergone rigorous QA/QC prior to publication.

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