Influence of coastal eddies and counter-currents on the influx of spiny lobster, Panulirus argus, postlarvae into Florida Bay

2001 ◽  
Vol 52 (8) ◽  
pp. 1217 ◽  
Author(s):  
Cynthia Yeung ◽  
David L. Jones ◽  
Maria M. Criales ◽  
Thomas L. Jackson ◽  
William. J. Richards
Keyword(s):  
Current Flow ◽  
Spiny Lobster ◽  
Mesoscale Eddy ◽  
Florida Bay ◽  
Florida Keys ◽  
Larval Transport ◽  
Panulirus Argus ◽  
Counter Current Flow ◽  
Highly Correlated ◽  
Counter Current

Postlarvae of the spiny lobster Panulirus argus migrate from offshore in the Florida Keys into their juvenile habitat in Florida Bay through interisland channels. The influx of postlarvae was monitored monthly over the new-moon period at Long Key and Whale Harbor channels (July 1997–June 1999). Although the channels were only 30 km apart, their influx patterns differed. At Long Key, influx peaked every 2–3 months, whereas at Whale Harbor the peaks were in winter and of higher magnitudes. The influx pattern at Long Key was highly correlated with the strength of coastal counter-current flow in the two-week period prior to sampling. Countercurrent flow was correlated with alongshore (upstream) wind stress, but the latter was not a significant predictor of postlarval influx. Coastal counter-current flow is hypothesized to indicate the presence of a cyclonic, mesoscale eddy offshore. Satellite imagery confirmed the presence of these eddies offshore of the Middle Florida Keys often when positive postlarval influx and counter-current anomalies were observed. These eddies can facilitate onshore larval transport, and their variable temporal and spatial properties can cause transport variability over a scale of several tens of kilometres along the Keys.

scholarly journals Effects of ghost fishing lobster traps in the Florida Keys

2015 ◽  
Vol 72 (suppl_1) ◽  
pp. i185-i198 ◽  
Author(s):  
Casey B. Butler ◽  
Thomas R. Matthews
Keyword(s):  
Atlantic Ocean ◽  
Spiny Lobster ◽  
Florida Bay ◽  
Florida Keys ◽  
Median Absolute Deviation ◽  
Panulirus Argus ◽  
Combined Effects ◽  
Absolute Deviation ◽  
Dead Fish ◽  
The Dead

AbstractGhost fishing is the capacity of lost traps to continue to catch and kill animals. In the spiny lobster (Panulirus argus) fishery in Florida, the effects of ghost fishing are of particular concern, given the estimated 10s of 1000s of traps lost annually. We distributed 40 each of the three types of lobster traps (wire, wood–wire hybrid, and wood slat) at three locations in the Florida Keys to simulate ghost fishing. Divers monitored these traps biweekly for 1 year then monthly for two additional years, recording the time ghost traps remained intact and continued to fish, as well as the number of live and dead lobsters and other animals in each trap. Wood slat and hybrid traps remained intact and fished for 509 ± 97 (median ± median absolute deviation) and 480 ± 142 d, respectively. Wire traps fished significantly longer (779.5 ± 273.5 d, p < 0.001), and several fished until the end of the experiment (1071 d). Traps in Florida Bay fished longer (711.5 ± 51.5 d) than traps inshore (509 ± 94.5 d) and offshore (381 ± 171 days; p < 0.001) in the Atlantic Ocean. More lobsters were observed in hybrid traps (mean = 4.81 ± 0.03 s.e.) than in wood slat (3.85 ± 0.16) or wire traps (3.17 ± 0.03; F = 40.15, d.f. = 2, p < 0.001). Wire traps accounted for 83% of fish confined overall and 74% of the dead fish observed in traps. Ghost traps in Florida Bay and Atlantic inshore killed 6.8 ± 1.0 and 6.3 ± 0.88 lobsters per trap annually, while Atlantic offshore traps killed fewer (3.0 ± 0.69) lobsters, likely as a result of lower lobster abundance in traps. The combined effects of greater lobster mortality and greater abundance of lost traps in inshore areas account for the majority of the estimated 637 622 ± 74 367 (mean ± s.d.) lobsters that die in ghost traps annually.

scholarly journals Directly ageing the Caribbean spiny lobster, Panulirus argus with validated band counts from gastric mill ossicles

2018 ◽  
Vol 76 (2) ◽  
pp. 442-451 ◽  
Author(s):  
Gaya Gnanalingam ◽  
Mark J Butler ◽  
Thomas R Matthews ◽  
Emily Hutchinson ◽  
Raouf Kilada
Keyword(s):  
Spiny Lobster ◽  
Age Determination ◽  
Florida Keys ◽  
Panulirus Argus ◽  
Gastric Mill ◽  
Coefficients Of Variation ◽  
The Caribbean ◽  
First Time ◽  
Reader Experience

Abstract In crustaceans, ecdysis was long believed to result in the loss and replacement of all calcified structures, precluding the use of conventional ageing methods. However, the discovery of bands in the gastric ossicles of several crustaceans with some correlation with age suggests that direct age estimation may be possible. We applied this method to a tropical spiny lobster, Panulirus argus, one of the most iconic and economically valuable species in the Caribbean. The presence of growth bands was investigated using wild lobsters of unknown age and was validated with captive reared lobsters of known age (1.5–10 years) from the Florida Keys, Florida (USA). Bands were consistently identified in ptero- and zygo-cardiac ossicles of the gastric mill and did not appear to be associated with moulting. Validation with known age animals confirms that bands form annually. Counts between independent readers were reproducible with coefficients of variation ranging from 11% to 26% depending on reader experience and the structure used. This study demonstrates, for the first time, that direct age determination of P. argus is possible.

Hydrodynamics of gas–liquid counter-current flow in solid foam packings

2005 ◽  
Vol 60 (22) ◽  
pp. 6422-6429 ◽  
Author(s):  
C.P. Stemmet ◽  
J.N. Jongmans ◽  
J. van der Schaaf ◽  
B.F.M. Kuster ◽  
J.C. Schouten
Keyword(s):  
Current Flow ◽  
Solid Foam ◽  
Counter Current Flow ◽  
Counter Current
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