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While juvenile Atlantic goliath grouper, Epinephelus itajara (Lichtenstein, 1822), are known to depend on mangrove root structure, relationships with water properties (e.g., salinity) and depth remain unclear or understudied. Because availability of suitable mangrove habitat has been suggested as the primary bottleneck to the recovery of this threatened species in the US, we investigated habitat associations of juvenile Atlantic goliath grouper with respect to physical water properties within mangrove habitats. Our study was conducted in six coastal rivers and three canals within the Ten Thousand Islands region of southwest Florida. Results suggested that juvenile Atlantic goliath grouper differed in how they associated with specific mangrove habitats based on season and size. We found that smaller juveniles (<340 mm TL) appeared to have stronger associations to physical water characteristics than larger (≥340 mm TL) juveniles. Both large and small juveniles showed the strongest associations with DO (i.e., >3 mg L −1 ) within mangrove habitat. For small juveniles, extreme temperatures influenced habitat association; for large juveniles, extreme salinity influenced distribution. We also found evidence that juvenile Atlantic goliath grouper associated more with natural rivers over man-made canals. The present study has utility for delineating suitable mangrove habitats for protection and potentially in the design of sampling surveys that aim to estimate population abundance.

We implanted individually coded acoustic transmitters into 40 adult winter flounder Pseudopleuronectes americanus (mean total length = 320 mm; range = 240–423 mm) and monitored them by use of passive acoustic telemetry from September 2007 to April 2009 to classify spatial and temporal movement patterns and quantify residency in Shinnecock Bay, eastern Long Island, New York. Overall, 94,250 valid detections were received. Winter flounder remained inshore, and 89% of the total detections occurred between May and October when bottom water temperature exceeded 15°C. Residency in Shinnecock Bay was dependent on time of release and varied greatly from a few weeks to more than 6 months; total presence (number of days on which individual fish were detected within the bay) averaged 22.0 d (range = 1–132 d). Tracked winter flounder were classified as exhibiting three movement patterns: (1) inner bay movements (short term versus long term), (2) dispersal to offshore waters, and (3) connectivity to other inshore areas. The first two patterns were consistent with historical notions of spatially overlapping resident and migratory individuals, whereas fish that displayed the third pattern may have exhibited a larger home range. These results provide insight into winter flounder movements, residency, and stock structure in a coastal bay of Long Island and provide important information for management. The interaction of exploitation and divergent migration behaviors may be a factor contributing to the winter flounder's decline in Long Island bays; however, more work will be required to obtain a full understanding of the spatial behavior and stock structure of this species.