Biomass, Yield Models, and Management Strategies for the Gulf of Mexico Ecosystem 1

Author(s):  
Bradford E. Brown ◽  
Joan A. Browder ◽  
Joseph Powers ◽  
Carole D. Goodyear
2020 ◽  
Vol 16 (2) ◽  
pp. 20190865 ◽  
Author(s):  
Stephen G. Hesterberg ◽  
Gregory S. Herbert ◽  
Thomas J. Pluckhahn ◽  
Ryan M. Harke ◽  
Nasser M. Al-Qattan ◽  
...  

The Gulf of Mexico (GoM) is home to the world's largest remaining wild oyster fisheries, but baseline surveys needed to assess habitat condition are recent and may represent an already-shifted reference state. Here, we use prehistoric oysters from archaeological middens to show that oyster size, an indicator of habitat function and population resilience, declined prior to the earliest assessments of reef condition in an area of the GoM previously considered pristine. Stable isotope sclerochronlogy reveals extirpation of colossal oysters occurred through truncated life history and slowed growth. More broadly, our study suggests that management strategies affected by shifting baselines may overestimate resilience and perpetuate practices that risk irreversible decline.


2006 ◽  
Vol 33 (2) ◽  
pp. 109-117 ◽  
Author(s):  
M. LUISA MARTÍNEZ ◽  
JUAN B. GALLEGO-FERNÁNDEZ ◽  
JOSÉ G. GARCÍA-FRANCO ◽  
CORAL MOCTEZUMA ◽  
CLAUDIA D. JIMÉNEZ

Human population density is globally three times higher along the coasts than inland, and thus environmental impacts of human activities are greater in magnitude on coastal ecosystems such as beaches and dunes. Vulnerability assessment (the loss of capacity to return to the original dynamic state after system displacement) is thus necessary to evaluate the conservation status and determine the most relevant disturbance events. Twenty-six sites along 902 km of Gulf of Mexico coastline, varying in conservation status and sedimentary dynamics, were sampled. At each site a vulnerability index (VI) was calculated based on variables that described geomorphological condition, marine influence, aeolian influence, vegetation condition and human effects. Vulnerability was very variable along the coast and only 19% of the sampled locations (mostly in the central Gulf of Mexico) displayed low vulnerability. Cluster analyses of the values assigned to the checklists for each location grouped the studied sites into three, according to their VI values. Low vulnerability locations had abundant sediment supply and low human impact. Locations with medium to high VI were mostly affected by their natural geomorphological and marine features and had medium to intense human activities. Management strategies should consider the observed variability in vulnerability, the natural dynamics of these systems and the role of human activities and interests, in order to achieve adequate policies and establish well-informed priorities for integrated coastal zone management.


2018 ◽  
Vol 10 (1) ◽  
pp. 24-39 ◽  
Author(s):  
M. D. Masi ◽  
C. H. Ainsworth ◽  
I. C. Kaplan ◽  
M. J. Schirripa

2021 ◽  
Vol 42 ◽  
pp. 101626
Author(s):  
Heber Zea-de la Cruz ◽  
Javier Tovar-Ávila ◽  
César Meiners-Mandujano ◽  
Lourdes Jiménez-Badillo ◽  
Jorge Luis Oviedo-Pérez

<em>Abstract.</em>—The red snapper <em>Lutjanus campechanus </em>fishery is arguably one of the most important in the Gulf of Mexico, but habitat destruction, climate change, and serial overfishing has resulted in significant population declines in red snapper and other high-profile fisheries species. The red snapper fishery may be one of the best examples where management strategies that promote catch and release (CAR) have failed. Populations have not recovered despite CAR management strategies, likely because CAR mortality is high; however, the basis for CAR mortality is unclear. Numerous studies associated with fishing-induced mortality were reviewed in an attempt to make generalizations as to how red snapper and other high-profile fisheries species respond to CAR. A framework for understanding CAR mortality in red snapper and other species was constructed based on four pillars: retrieval conditions, species and size relationships, handling, and release conditions. Each of these fishing factors was examined as to relative impact toward CAR. A predictive model was generated from all available data on CAR mortality. For a deep-water fish like red snapper, the underlying problem is directly related to capture depth, particularly injuries related to rapid swim bladder (SB) overinflation and catastrophic decompression syndrome (CDS). If not immediately lethal, depth-related injuries may have long term effects on growth and immune function that could go unnoticed and are unaccounted for in traditional field studies; all other fishing factors will only intensify this baseline impairment. Management plans are typically built under the assumption that CAR mortality is below 20%, but it is widely accepted that this is a gross underestimate. Modeling from this review suggests that, in red snapper, mortality may be as low as 20% but only if fish are caught between 0 and 20 m depths. This is not the case, and CAR mortality may reach 100% if fish are retrieved from deeper than 110 m. Current CAR management strategies are ineffective, and not enough information exists to impose maximum fishing depths. Given these limitations, a logical approach would be to restrict particular areas such that fish populations can be protected from all fishing and CAR activity, therefore protecting age, size, and sex classes and ratios. For fish species like red snapper, where overfishing is widespread and CAR mortality is high, or other species where CAR is unclear and a thorough investigation as to depth-related CAR mortality has not been performed, strategies based on space (i.e., marine protected areas and no-take reserves), rather than time or numbers (i.e., season closures, size limits, bag limits, etc.), have the greatest potential for overall conservation and sustainability and should be strongly considered.


2021 ◽  
Author(s):  
Samaneh Soroush ◽  
Debbie Lu ◽  
Tommy Golczynski ◽  
Christopher Jake White ◽  
Tony Spratt

Abstract Gas hydrate formation in natural gas systems and subsea infrastructure can block pipelines and instruments, restrict flow, and lead to safety and environmental hazards in production and/or transportation systems. These problems can lead to substantial economic and HSE risks. Therefore, understanding how, when and where hydrate formation occurs are important factors in developing the hydrate management strategies. This paper addresses the hydrate management strategy in one of the subsea developments in the Gulf of Mexico (GOM). The effects of salinity, water cut, and amount of methanol on hydrate formation and plugging risk were studied in this paper. The experimental results and modeling in advanced thermodynamics software showed that an increase in the concentration of methanol and salts in the autoclave cell leads to a shift of the equilibrium curves, reducing subcooling and hydrate volume fraction while increasing induction time. The results also show that for some under-inhibited systems, the volume fraction of the hydrate slurry is low enough to allow for safe transportation of fluids during various operational conditions.


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