Subsurface gas hydrates in the northern Gulf of Mexico

The northern Gulf of Mexico (GoM) has long been a focus area for the study of gas hydrates. Throughout the 1980s and 1990s, work focused on massive gas hydrates deposits that were found to form at and near the seafloor in association with hydrocarbon seeps. However, as global scientific and industrial interest in assessment of the drilling hazards and resource implications of gas hydrate accelerated, focus shifted to understanding the nature and abundance of “buried” gas hydrates. Through 2005, despite the drilling of more than 1200 oil and gas industry wells through the gas hydrate stability zone, published evidence of significant sub-seafloor gas hydrate in the GoM was lacking. A 2005 drilling program by the GoM Gas Hydrate Joint Industry Project (the JIP) provided an initial confirmation of the occurrence of gas hydrates below the GoM seafloor. In 2006, release of data from a 2003 industry well in Alaminos Canyon 818 provided initial documentation of gas hydrate occurrence at high concentrations in sand reservoirs in the GoM. From 2006 to 2008, the JIP facilitated the integration of geophysical and geological data to identify sites prospective for gas hydrate-bearing sands, culminating in the recommendation of numerous drilling targets within four sites spanning a range of typical deepwater settings. Concurrent with, but independent of, the JIP prospecting effort, the Bureau of Ocean Energy Management (BOEM) conducted a preliminary assessment of the GoM gas hydrate petroleum system, resulting in an estimate of 607 trillion cubic meters (21,444 trillion cubic feet) gas-in-place of which roughly one-third occurs at expected high concentrations in sand reservoirs. In 2009, the JIP drilled seven wells at three sites, discovering gas hydrate at high saturation in sand reservoirs in four wells and suspected gas hydrate at low to moderate saturations in two other wells. These results provide an initial confirmation of the complex nature and occurrence of gas hydrate-bearing sands in the GoM, the efficacy of the integrated geological/geophysical prospecting approach used to identify the JIP drilling sites, and the relevance of the 2008 BOEM assessment.     

Sediment community oxygen consumption in the deep Gulf of Mexico

Sediment community oxygen consumption (SCOC) has been measured from the continental shelf out to the Sigsbee Abyssal Plain in the NE Gulf of Mexico (GoM). SCOC rates on the continental shelf were an order of magnitude higher than those on the adjacent continental slope (450–2750 m depth) and two orders of magnitude higher than those on the abyssal plain at depths of 3.4–3.65 km. Oxygen penetration depth into the sediment was inversely correlated with SCOC measured within incubation chambers, but rates of SCOC calculated from either the gradient of the [O₂] profiles or the total oxygen penetration depth were generally lower than those derived from chamber incubations. SCOC rates seaward of the continental shelf were lower than at equivalent depths on most continental margins where similar studies have been conducted, and this is presumed to be related to the relatively low rates of pelagic production in the GoM. The SCOC, however, was considerably higher than the input of organic detritus from the surface-water plankton estimated from surface-water pigment concentrations, suggesting that a significant fraction of the organic matter nourishing the deep GoM biota is imported laterally down slope from the continental margin.     

Growth rates,densities, and distribution of Lophelia pertusa on artificial structures in the Gulf of Mexico

Using industry inspection video and ROV imaging, we examined Lophelia pertusa (Linnaeus 1758) on 10 artificial structures of known ages (9 to 100 years) in the northern Gulf of Mexico (GoM). Five different types deep-water energy installations with depths ranging from 320 to 995 m, and three shipwrecks with depths ranging from approximately 530 to 615 m, were examined. Density, depth ranges, and growth rates of L. pertusa colonies were calculated from video and image analysis. L. pertusa colonies were present on all structures examined. Minimum calculated growth rates for the largest colonies ranged from 0.32 to 3.23 cm/yr on the different structures. The shallowest depth at which L. pertusa was observed was 201 m and the deepest was 801 m, considerably expanding the known depth range of this species in the northern GoM. Colony density varied with structure type, age, and depth, with the highest density between 503 and 518 m on the single structure that spanned the entire depth range of occurrence of L. pertusa observed in this study. L. pertusa colonies growing on thinner and deeper installations appear to have higher colonization rates, i.e. to develop higher densities over a shorter time period, compared to those on shallower and more massive types of installations. However, on average, colonies have slower growth rates on these installations than colonies on more massive, shallower installations (compliant and solid installations). In general, the calculated minimum growth rates were higher on the installations than on the shipwrecks, which were substantially older. A continuum of colony sizes was documented on all installations, suggesting multiple settlement events. L. pertusa thickets were observed on the oldest anthropogenic structures, with most of the components of these structures covered by colonies of L. pertusa. Brown, orange, and mottled color-variants were documented for the first time in the GoM. All installations examined for this study were colonized by L. pertusa and it is likely that most artificial surfaces in appropriate depths in the GoM will be as well.     

Contrasting perspectives on mangroves in arid Northwestern Mexico: Implications for integrated coastal management

Mangroves in Northwestern Mexico are vital to maintain coastal environments healthy, to provide nutrients for several food chains, and to supply valuable goods and services that sustain and improve human livelihoods. Many of these values offer a range of opportunities for economic development that attract workers, investors and developers. Recently, federal privatization policies have promoted an accelerated coastal development of this region to obtain large profits in short times, creating competing and overlapping interests to use coastal environments and control key resources. Such intense developments are modifying the ecological conditions of many coastal areas, threatening the provision of important ecosystem services to society. After years of centralized decisions, new paradigms are needed to achieve a coastal management that ensures long-term ecosystem maintenance, fair resource use and social equity. Recognizing the multiplicity of actors involved in coastal management and using a qualitative research methodology, we identified and explored the perspectives of different key stakeholders in the states of Baja California Sur and Sonora, Mexico, to better understand their views on mangroves use and management as well as the interaction among them. We discuss similarities and/or discrepancies found among stakeholders’ perceptions by describing their central ideas and identifying overlapping interests that may create conflicts when defining development and conservation programs or formulating policies. This information also intends to encourage further research on the social-ecological system of the coasts in Northwestern Mexico and to contribute to address coastal management issues in integrated ways that consider the social dimension through documenting stakeholders’ narratives in the future.     

Contextual factors influencing sustainable fisheries in Mexico

Sustainable fisheries take into consideration that managed fisheries ecosystems shift over time in response to evolving environmental as well as market and political factors. These contextual forces are especially valuable in understanding developing countries such as Mexico, where the unconsolidated fisheries administration faces productive marine ecosystems but unsustainable fisheries. To recognize the issues that have inhibited the consolidation of a regulatory system for sustainable fisheries, a contextual factor analysis was applied to the co-development of two current policies in the Mexican fishery regime: fisheries and environmental policies. Six historical phases have been identified in which there are few long periods of stability and frequent short periods of radical change that alternate between stable and adverse contextual situations. These short and contrasting contextual situations cause a kind of tug-of-war in Mexican fisheries policy-making. On the one hand, domestic economic, scientific, and technological forces seem to slowly lead toward the consolidation of sustainable fisheries; on the other hand, domestic policies drift from one position to another at other timing than the international fisheries and environmental policies. Although recent crises seem to highlight new periods of radical change in Mexico, they also provide an opportunity to adopt new structural plans to consolidate domestic forces as a basis for long-term strategies.     

The unintended consequences of formal fisheries policies: Social disparities and resource overuse in a major fishing community in the Gulf of California, Mexico

This study investigates the local social and fisheries impact of formal fisheries policies in Bahía de Kino, one of the most important fishing villages in terms of extraction of benthic resources in the Northern Gulf of California, Mexico. The paper focuses on cross-scale institutional interactions, describing how existing formal policies are functioning on the ground, how these policies interact with local arrangements, and how this interaction may affect the incentives of different actors towards sustainable fisheries. Besides providing lessons on how the performance of a local fishery could be improved, this paper addresses the question of whether the formal institutional structure of Mexican fishing regulations is effective in promoting responsible behavior by small-scale fishery stakeholders. It is argued that the design of the most widely used management tool to regulate access to marine resources throughout Mexico -the permit (licensing) system- provides the wrong incentives for sustainable-use. Granting secure rights to resources to those actively involved in the fishery is a necessary step for promoting sustainable fishing practices.     

Subsidies in the jumbo squid fishery in the Gulf of California,Mexico

This paper investigates the effects of fuel subsidies and value added tax refunds on the operation of two types of firms associated with the jumbo squid (Dosidicus gigas) fishery in Mexico: (a) firms with ships that catch shrimp and squid in different periods of the year and (b) firms that deploy outboard-motor boats to catch squid year-round. The cost-benefit ratios of the policies are analyzed for 2008–2015, both with and without subsidy-related income. Additionally, the net cash surplus is calculated. The elimination of subsidies may affect jobs related to vessel operations in the squid fishery and may also encourage the voluntary retirement of shrimp ships. This effect is less evident in the case of the smaller boats. Strategies aimed at improving the landed squid prices are nonetheless suggested.     

Cetacean habitat in the northern oceanic Gulf of Mexico

Cetaceans (whales and dolphins) are diverse and abundant upper trophic level predators in the Gulf of Mexico, a semi-enclosed, intercontinental sea with a total area of about 1.5 million km². The objectives of this study were to better define the habitat of cetaceans in the northern oceanic Gulf of Mexico. An integrated methodology was used that included visual surveys and hydrographic collections from ships. Near real-time sea surface altimetry from the TOPEX/POSEIDON and ERS satellites was used during ship surveys to determine the location of hydrographic features (e.g., cyclones, anticyclones and confluence zones). Archival satellite sea surface altimetry data were also used to retrospectively determine the location of hydrographic features for analysis with earlier cetacean sightings. We estimated zooplankton and micronekton biomass using both net and acoustic sampling to indicate the amount of potential food available for higher trophic level foraging by cetaceans. Nineteen cetacean species were identified during ship surveys. Cetaceans were concentrated along the continental slope in or near cyclones and the confluence of cyclone–anticyclone eddy pairs, mesoscale features with locally concentrated zooplankton and micronekton stocks that appear to develop in response to increased nutrient-rich water and primary production in the mixed layer. A significant relationship existed between integrated zooplankton biomass and integrated cephalopod paralarvae numbers, indicating that higher zooplankton and micronekton biomass may correlate with higher concentrations of cetacean prey. In the north-central Gulf, an additional factor affecting cetacean distribution may be the narrow continental shelf south of the Mississippi River delta. Low salinity, nutrient-rich water may occur over the continental slope near the mouth of the Mississippi (MOM) River or be entrained within the confluence of a cyclone–anticyclone eddy pair and transported beyond the continental slope. This creates a deep-water environment with locally enhanced primary and secondary productivity and may explain the presence of a resident, breeding population of sperm whales within 100 km of the Mississippi River delta. Overall, the results suggest that the amount of potential prey for cetaceans may be consistently greater in the cyclone, confluence areas, and south of the MOM, making them preferential areas for foraging. However, this may not be true for bottlenose dolphins, Atlantic spotted dolphins and possibly Bryde's whales, which typically occur on the continental shelf or along the shelf break outside of major influences of eddies.     

Fishermen perception on resources management and aquaculture development in the Mecoacan estuary,Tabasco, Mexico

The southern Mexican states on the coast of the Gulf of Mexico produce approximately 85% of the total national oil production. The region has also attracted attention due its important economic influence in terms of fisheries, aquaculture and agriculture, and for its ecosystem diversity. The justification for more integrated approaches to aquaculture development is significant, as coastal aquaculture has brought economic and employment benefits to both national economies and coastal people. The aim of this study is the analysis of Mecoacan fishing communities’ perception on coastal resources management and to assess group awareness of the potential benefits and impacts of coastal aquaculture. Although aquaculture practices have been implemented as an alternative to fishing and to improve current levels of fisheries production, the results showed that conditions within Mecoacan fisheries have deteriorated significantly, as collective aggregation is not producing a positive outcome for the local communities. However, fishermen regarded the restructuring of fishing organisations as a means of integrating employment and income generation alternatives such as aquaculture practices. Therefore, a key to success will be to demonstrate the ability of good coastal management to promote capacity building within coastal communities in the context of a participatory intervention strategy through formal and informal organisations.     

The coast of Mexico: approaches for its management

The Mexican coast can be regionalized according to the main economic activities performed in it; for the purpose of this work we are considering five regions: North Pacific, Mar de Cortes, outh Pacific, Gulf of Mexico, and Caribbean. According to the national census, the population of the coastal zone in Mexico is increasing at a higher rate than the national average. The main industries located in the coastal and marine zones are oil and gas, fisheries, aquaculture, tourism, maritime transportation and ports, chemical industries, and minerals. Mexico has developed an environmental legal framework based on the Ley General del Equilibrio Ecologico y la Proteccion al Ambiente (LGEEPA), and the coastal management paradigm is strengthened through several other legal tools developed specifically for this purpose. There are three management strategies identified in this work for the coastal zone in Mexico: (1) Agency Leadership, (2) Protected Areas, and (3) Land Ordinance. Each one of these strategies includes stages for eventually developing an Integrated Coastal Zone Management (ICZM) plan that considers vertical and horizontal integration, scientific research of natural resources and ecosystems, and socioeconomic issues.     

Integrating science and management on coastal marine protected areas in the Southern Gulf of Mexico

The coastal zone of the State of Campeche have some of the Gulf of Mexico’s richest ecosystems characterized by extensive seagrasses, mangrove forests, low-land tidal wetlands, a broad deltaic environment, including the Usumacinta/Laguna de Terminos estuarine ecosystem, and extensive low salinities and brackish wetlands in the Petenes region. Commercial and artisanal fishing, maritime transport, agriculture and cattle grazing in low-land areas, urban expansion, building of highways, and tourism, are important economics activities that are increasing in the State of Campeche. However, the growth needs to occur in a sustainable manner with adequate protection of the coastal ecosystems. The theoretical approach and conceptual basis of the integrated coastal management plan are based on 20 years of scientific research in the region; and from 1990 to the present, a number of projects have been completed which serve as case studies of coastal management coupling science, technology, public participation, and policymaking in the southern Gulf of Mexico. After developing seven “study case” integrating science into policymaking, a management approach was developed considering four main actions: promotion of institutional arrangements, so that the multi-sectorial planning approach be considered in coastal resources development; strengthening of public awareness related to coastal resources management policies and capabilities; gathering, analysis and dissemination of information related to coastal resources development; and provision of technical solutions to coastal resources uses in conflict. Finally this is a case study where science played a significant role in the politics of the policy process, both in protecting key estuarine ecosystem and the planning process defining the ICZM plans.     

Fisheries learning exchanges and sea turtle conservation: An effort between Mexico,Cuba and the U.S. to engage Cuban coastal communities in non-consumptive alternative behaviors

The purpose of this short communication is to describe the Third International Workshop on Sea Turtle Conservation and Fisheries Exchange that took place from April 22–30, 2009 on Cuba’s Isla de la Juventud [Isle of Youth]. A group of 28 fishers, conservationists, marine scientists and fisheries managers from Cuba, Mexico and the U.S. gathered at Siguanea Bay off the island’s southwest coast. The goals of the exchange were to 1) provide a forum for sea turtle experts and fishing communities in Cuba, Mexico, and the U.S. to share experiences on conservation activities, 2) develop the scientific basis for future conservation in this highly biologically important region of Cuba, and 3) increase support by Cuban fishers for local sea turtle conservation efforts. During the exchange, participants met with local Cuban fishers about the challenges of conserving sea turtle populations while maintaining their fishing livelihoods, shared solutions developed by fishers to accomplish the same in Mexico, and undertook field and cultural activities. Key outcomes for the exchange include an improved understanding of sea turtle bycatch off the Isla de la Juventud, enhanced collaboration among the three nations in turtle conservation, and increased motivation by fishers to participate in sea turtle research and conservation. Additionally, as a direct result of this exchange, the community of Cocodrilo on the Isla de la Juventud has hosted annual sea turtle festivals that increase support for turtle conservation efforts by the local community.     

Governance and effects of marine reserves in the Gulf of California,Mexico

We trace the evolution, governance, and effects of three marine reserve (no-take zones) initiatives in the Gulf of California, Mexico: Loreto Bay National Park, Puerto Peñasco, and San Pedro Mártir Island Biosphere Reserve. Preliminary monitoring results, although highly variable, are encouraging for conservation and fisheries management. However, open access situations and differing conceptions among local stakeholders and government concerning access rights to fishing grounds, coupled with limited support for surveillance and lags between local and government institutional arrangements and interests, are the main constraints for the success of these and future reserves in the region. We discuss the main social–ecological feedbacks at play and the implications of our findings within a regional context.     

Comparative biomass structure and estimated carbon flow in food webs in the deep Gulf of Mexico

A budget of the standing stocks and cycling of organic carbon associated with the sea floor has been generated for seven sites across a 3-km depth gradient in the NE Gulf of Mexico, based on a series of reports by co-authors on specific biotic groups or processes. The standing stocks measured at each site were bacteria, Foraminifera, metazoan meiofauna, macrofauna, invertebrate megafauna, and demersal fishes. Sediment community oxygen consumption (SCOC) by the sediment-dwelling organisms was measured at each site using a remotely deployed benthic lander, profiles of oxygen concentration in the sediment pore water of recovered cores and ship-board core incubations. The long-term incorporation and burial of organic carbon into the sediments has been estimated using profiles of a combination of stable and radiocarbon isotopes. The total stock estimates, carbon burial, and the SCOC allowed estimates of living and detrital carbon residence time within the sediments, illustrating that the total biota turns over on time scales of months on the upper continental slope but this is extended to years on the abyssal plain at 3.6 km depth. The detrital carbon turnover is many times longer, however, over the same depths. A composite carbon budget illustrates that total carbon biomass and associated fluxes declined precipitously with increasing depth. Imbalances in the carbon budgets suggest that organic detritus is exported from the upper continental slope to greater depths offshore.The respiration of each individual “size” or functional group within the community has been estimated from allometric models, supplemented by direct measurements in the laboratory. The respiration and standing stocks were incorporated into budgets of carbon flow through and between the different size groups in hypothetical food webs. The decline in stocks and respiration with depth were more abrupt in the larger forms (fishes and megafauna), resulting in an increase in the relative predominance of smaller sizes (bacteria and meiofauna) at depth. Rates and stocks in the deep northern GoM appeared to be comparable to other continental margins where similar comparisons have been made.     

Middlemen,informal trading and its linkages with IUU fishing activities in the port of Progreso,Mexico

This paper explores the economic environment that makes informal fish trading possible, the nature of these activities and how they are interconnected or might stimulate IUU fishing activities in the port of Progreso, Yucatan, Mexico. The main argument is that fish trading by middlemen has been developed within the scope of an informal sector which depends on the existence of structural and organizational factors such as: a dual economic system where the formal and informal sectors are complementary, and an institutional environment and a socio-economic network that interconnects both sectors and supports the activity. Research for this study was carried out during 2008 and 2009 in the port of Progreso, Yucatan, Mexico. The survey strategy was a non-probability sample adapting and combining chain referral techniques because middlemen in this region are a hidden population. Findings indicate that the main motivation for middlemen to remain underground is to maximize benefits. In order to do so, they need to build a socioeconomic network which is the center of their trading system. This way of operating generates incentives for fishers to fish illegally because middlemen would buy their products even if they do not meet formal regulations.     

Geochemical constraints on the distribution of gas hydrates in the Gulf of Mexico

Gas hydrates are common within near-seafloor sediments immediately surrounding fluid and gas venting sites on the continental slope of the northern Gulf of Mexico. However, the distribution of gas hydrates within sediments away from the vents is poorly documented, yet critical for gas hydrate assessments. Porewater chloride and sulfate concentrations, hydrocarbon gas compositions, and geothermal gradients obtained during a porewater geochemical survey of the northern Gulf of Mexico suggest that the lack of bottom simulating reflectors in gas-rich areas of the gulf may be the consequence of elevated porewater salinity, geothermal gradients, and microbial gas compositions in sediments away from fault conduits.     

Interactions between the Laramide Foreland and the passive margin of the Gulf of Mexico: Tectonics and sedimentation in the Golden Lane area,Veracruz State,Mexico

This paper focuses on the analyses of the clastic sedimentary infill of the Coastal Plain of Eastern Mexico, which initiated synchronously with the Laramide orogeny in the vicinity of the Golden Lane. Results of these analyses are used as boundary conditions for calibrating/interpreting seismic profiles across more distal depocenters in the offshore of the Gulf of Mexico, from the sea shore and continental slope in the west to the abyssal plain in the east. The objective of the study is to better predict the reservoir distribution in the Deep offshore Basin of the Gulf of Mexico (DBGM), in order to explore for petroleum.     

Spatial analysis of the impact of shrimp culture on the coastal wetlands on the Northern coast of Sinaloa, Mexico

In the Mexican coasts, as in many tropical and subtropical coastal areas, shrimp culture grew exponentially over the last three decades. This process has produced an intense debate on the economic benefits but also about the extent and intensity of the impact of this activity on the coastal ecosystems, particularly the effects of pond construction on mangrove areas and other coastal wetlands. For the Northern coast of Sinaloa (Northwest Mexico), a region where shrimp culture is actively practiced and reproduces most of the shrimp controlled production model in Mexico, a land cover change-detection analysis, with Landsat images, outputs that 75% of the shrimp farming in this region has been built on saltmarshes while less than 1% was constructed on mangrove areas. Through the estimation of landscape metrics for different scenarios (with and without shrimp culture infrastructure), we find that in addition to direct removal of saltmarshes, shrimp aquaculture has significantly modified the spatial patterns of coastal wetlands, retreating wetland borders and fragmenting their patches. These last impacts are mainly related with the development of the linear infrastructure associated with shrimp culture (drainage channels and roads), rather than the construction of the ponds. Present findings and other from similar studies done in Northwest Mexico; allow us to estimate that 60% of shrimp farming in Mexico impacted directly on saltmarshes, contrasting with the 3% of shrimp farms built on mangroves.     

Capacity,capability and cross-border challenges associated with marine eradication programmes in Europe: The attempted eradication of an invasive non-native ascidian,Didemnum vexillum in Wales,United Kingdom

Increasing recognition of the threat which invasive non-native species present to ecological and economic assets has led to a recent surge in international, regional and national policies. Within the European Union, a draft EU Regulation on the prevention and management of invasive alien species has been developed. The draft Regulation, published in 2013, recommends the creation of a list of invasive alien species of Union concern, wherein any Member State identifying newly establishing populations of these species must implement rapid eradication measures. The first recording of the invasive non-native ascidian Didemnum vexillum in Britain in 2008 in Wales, and subsequent eradication efforts, presents a timely opportunity to evaluate the United Kingdom׳s existing capability and capacity to undertake a rapid eradication in the marine environment in light of the draft EU Regulation, as well as highlighting some of the cross-border challenges facing the EU. Although the UK is often cited within Europe as having made significant progress in the field of invasion management, the lessons learned from the eradication process in Wales highlight that the UK is inadequately prepared to undertake rapid eradication measures in the marine environment and that the lack of a coordinated approach between nations has significant potential to devalue localised eradication efforts. A number of measures are discussed to enhance future capability both in the UK and the wider European Union including enhanced alerting mechanisms, science-based monitoring programmes to enable early detection, increased commitment of resources and the need for cross-border collaboration.