Two Shelf-Edge Marine Protected Areas in the Eastern Gulf of Mexico

The Madison-Swanson Marine Protected Area (MPA) and Pulley Ridge Habitat Area of Particular Concern (HAPC), two protected areas off the Florida shelf in the eastern Gulf of Mexico, were established by the Gulf of Mexico Fishery Management Council and the US National Oceanic and Atmospheric Administration to protect benthos-associated organisms. However, the types of organisms and the reasons for the protection are quite different. Madison- Swanson is used by an economically valuable reef fish species, the gag grouper, as a spawning ground. Pulley Ridge contains the deepest hermatypic scleractinian coral colonies in the continental USA. Biological assessments of these protected areas were carried out in generally similar fashion: initial mapping with multibeam sonar followed by targeted observations with remote still and video cameras. The formation of the Florida carbonate platform began when North America and Africa rifted apart during the opening of the Atlantic Ocean. The principal biological interest in Madison-Swanson was a large and mobile apex predator, while in Pulley Ridge it was a sessile invertebrate. The mobility, or lack thereof, of these biological targets shaped the biological assessment strategies. In Madison-Swanson, the initial effort was complete multibeam bathymetric and backscatter mapping. These maps were used to stratify the entire reserve into seven regions. The bathymetry was used to segregate the high-relief areas, while the backscatter data were used to differentiate low-relief areas with different sediment types. Remotely Operated Vehicle (ROV) video transects were surveyed to confirm the habitat types within each strata

Handle with Care: Establishing Catch Limits for Fish Stocks Experiencing Episodic Natural Mortality Events

Harmful blooms of the dinoflagellate Karenia brevis, known as "red tides," are responsible for major episodic fish kills in the Gulf of Mexico. In response to management concerns, we conducted a management strategy evaluation to examine whether decision-making reactivity to event occurrence or precautionary catch limit reductions could aid in achieving fishery objectives. Simulated stock dynamics were representative of Gulf of Mexico Red Grouper Epinephelus morio, and assessment of simulated data involved estimation of time-varying natural mortality. We found that both unresponsive yet precautionary catch limits and reactive decision making could improve achievement of fishery objectives, although practical impediments to reactive strategies abound. Where catch limit reductions were introduced to buffer against scientific uncertainty, a trade-off was evident that required recognizing constraints in stock assessment reliability (given the complexities of estimating time-varying natural mortality) and balancing these constraints against desirability for high catch rates. Our study provides a narrative on the ways in which management guidance can be structured to address uncertainty about future occurrences of episodic natural mortality events