Stephen J. Hall

Bio: Stephen J. Hall is an academic researcher from Australian Institute of Marine Science. The author has contributed to research in topics: Marine protected area & Fisheries management. The author has an hindex of 4, co-authored 6 publications receiving 792 citations.

The environmental cost of animal source foods

Abstract: A source food (ASF) production is one of the most dynamic elements of the world food system. Livestock production has been increasing at an average of 2.46% per year from 1993 to 2013 (data obtained from FAOSTAT; www.fao. org/faostat/en/#data/CL) and aquaculture, which increased at an average of 5.79% per year from 2009 to 2014 (FAO 2016), more than compensated for the slight (0.3% per year) decline in production from capture fisheries over the same period (FAO 2010, 2012). Both production and demand for ASFs is expected to continue to rise (Godfray et al. 2010), driven by world population growth and rising incomes in many countries (Hazel and Wood 2008). The environmental consequences of ASF production have received considerable scientific and public attention (Tilman et al. 2001; Steinfeld et al. 2006; Smith et al. 2010; Herrero et al. 2015) both with respect to the sustainability of production and the environmental consequences of alternative practices. A broad range of policy choices have influenced (and will continue to influence) the relative rate and location of growth of different forms of animal production. To make these choices, policy makers, retailers, and consumers must have greater access to more standardized information across a range of metrics about the relative environmental costs of alternative production methods when attempting to meet rising demand. There is a large and growing source of literature documenting the environmental impacts of different ASFs (eg Steinfeld et al. 2006; Pelletier et al. 2011). With the exception of energy use, however, there are no systematic comparisons of environmental costs across the different types of ASFs. Global and national agricultural policies, trade agreements, and environmental regulations guide decisions on expanding food production, and the ability to make systematic comparisons between different ASFs would allow these decisions to be better informed. The environmental impacts of food production can be considered from many perspectives, including the inputs (eg energy, fresh water, fertilizer, pesticides, antibiotics) and the consequences (eg greenhousegas [GHG] emissions, water use, water quality, biodiversity loss, habitat destruction) of food production methods. Many of these consequences were considered in the planning documents for the Millennium Ecosystem Assessment (WRI 2003) and some have been estimated for a wide range of production methods using lifecycle assessment (LCA), the established method for measuring multiple environmental impacts. We identified 148 individual LCAs for ASFs that evaluated major production methods in an effort to collate and systematize our understanding of the environmental impacts across the range of animal production methods. Of these studies, 48 were for livestock (meat), 29 were for capture fisheries, and 71 were for aquaculture. We also reviewed the literature for data The environmental cost of animal source foods

The continental shelf benthic ecosystem: current status, agents for change and future prospects

Abstract: Continental shelf benthic ecosystems play an important role in the economy of many coastal states through the provision of food, non-living resources and through control of climate. Changes in the status of these ecosystems, through either natural or human-induced environmental drivers can be expected to have important economic and social consequences. Agents that could induce change include climate and oceanography, hydrology (river discharge), land-use and waste disposal practices, fishing, aquaculture and extraction of non-living resources. Trends in all of these drivers, particularly those under human influence, suggest that shelf systems will come under increasing pressure. Attempts to predict the future state of any ecological system are fraught with difficulty, particularly over decadal time-frames. This is, perhaps, especially true for continental shelf ecosystems where data on current status are poor and our understanding of many of the drivers of change somewhat rudimentary. What can be said for certain, however, is that change will occur and, in the short term, many of the signs point towards deterioration in the ecological condition of many shelf systems, but particularly those of developing countries. Trends in land-use practices, with consequences for nutrient, sediment and freshwater input to coastal seas appear to be particularly worrying, but the poor state of many demersal fisheries systems must also be acknowledged. In contrast to the developing world, although challenges undoubtedly remain, particularly with respect to atmospheric inputs resulting from energy production, current trends in environmental management suggest that pressures imposed by land use, waste disposal and fishing will probably decline over the coming decades on the shelves of many developed countries. At the global scale, therefore, the key driver for sustainable use of our continental shelf ecosystems would appear to be intimately linked to the social and economic well-being of poorer nations.

Is offshore oil exploration good for benthic conservation

Abstract: The conservation value of seabed communities varies with location. In particular, a rich sessile epifauna (e.g. sponges and corals) is generally viewed as being of higher value than a species-poor sediment surface, even if this surface supports high diversity below ground. Intrinsic aesthetic appeal, greater vulnerability to activities such as trawling, and their potential importance as a habitat for commercial fish 1xSee all References1, make epifaunal communities particularly worthy of conservation. That the oil industry might represent a positive force for conservation of epifauna is counter-intuitive. Recent events, however, have highlighted two aspects of the oil industry that support this proposition.A key feature of epifaunal communities is that they usually exhibit a patchy distribution, often occurring as small islands of biodiversity on a featureless seabed. Clearly, before such patches can be protected, they need to be located. However, acting alone, most research institutes cannot commit the resources needed to conduct large-scale surveys to identify candidate areas for conservation. By contrast, the oil industry does have the resources and, as part of the licensing agreements for exploration, is usually required to undertake an environmental impact assessment. A recent example from the UK illustrates how such an assessment reaped rich scientific rewards that have benefited benthic conservation objectives.The oil companies operating in the deep water west of Shetland interact through a body known as the Atlantic Frontier Environmental Network [AFEN (http://www.oilandgas.org.uk/issues/home.cfm)]. Representatives of the government, oil industry and conservation bodies, under the auspices of AFEN, undertook large-scale survey work between 1996 and 1999 to document the benthic communities of the Middle Atlantic margin area that were licensed for oil and gas exploration. One species that has been known for 100 years to occur along the margins of the Scottish continental shelf is the cold water coral Lophelia pertusa. The AFEN surveys have provided a much more complete picture of both the distribution of this coral and the high biodiversity of associated organisms that Lophelia colonies support 1xSee all References1. As with many other epifaunal communities, these deep-water corals, which lack the symbiotic algae of their tropical counterparts, are very patchy and variable in their patterns of distribution. For example, Lophelia to the west of Shetland occurs as small bush-like structures, whereas in an area of about 20 km2 in deeper water, 1000 m off Cape Wrath, hundreds of seabed mounds of 100 m in diameter and 5 m in height have been discovered, many of which support Lophelia colonies 2xRice, T. and Owen, P. : 182See all References2.Although oil exploration and production might be a threat to these rich communities, the extent of the risk and the mechanisms of impact remain uncertain. Of course, this does not mean that the risks should not be determined; indeed, Lophelia was recently the subject of a successful high court action by Greenpeace against the UK Government, ensuring that the EU Habitats Directive now extends to offshore waters off the UK coast. In contrast to the threat from oil, however, the threat to Lophelia from trawling is much more obvious. From seamounts off Tasmania to Lophelia banks off the Norwegian coast there is growing evidence that deep-water corals are being affected by trawling activity 2xRice, T. and Owen, P. : 182See all References2. Thus, present evidence suggests that fishing is potentially a much greater threat to Lophelia than is the oil industry, in terms of both the spatial scale of the activity and its destructive capacity. The paradox is that the surveys undertaken by the oil industry are providing much needed distribution data, which could identify areas for protection from fishing.A second aspect of the Lophelia story concerns the other end of the oil-production cycle, when platforms come to the end of their useful life – a situation now arising in the North Sea. Faced with a large number of structures that need to be dealt with and the potential for costly controversy 2xRice, T. and Owen, P. : 182See all References2, the oil industry is closely examining all disposal options. At first sight, the preferred choice from a conservation perspective might seem to be complete removal. However, at least two issues argue against such action. First, the presence of oil platforms (or remnant structures on the seabed) could prevent further disturbance from fishing. Given the global momentum to establish Marine Protected Areas and the fact that the areas around platforms are already closed to fishing, there is merit in the idea that these areas should not be re-opened. The second argument concerns the epifaunal communities that oil platforms now support. Any hard substratum placed in the sea for any length of time is likely to be colonized by epifauna; however, there was some surprise when Lophelia colonies were found on North Sea platforms that are nearing the end of their life.If Lophelia and the diversity of species supported by its colonies are considered to be a valid target for conservation, the oil industry, which at first sight appears to be a threat, could, on closer inspection, be viewed as a benefit. Benthic ecologists urgently need landscape-scale distribution data on epibenthic communities on continental shelves to identify candidate areas for protection from fishing; oil exploration has the potential to provide these data. Oil production also provides hard substrates that encourage the growth of epifaunal communities. Although the value of artificial reefs remains controversial, once erected, there might be benefits to leaving these structures in place, even when oil production ceases. As with most issues, the more one looks, the more confusing things become – but no-one said marine conservation was straightforward!

Marine Protected Areas: a picture paints a thousand words

Abstract: There is now little doubt that differences in benthic community structure are detectable when highly trawled areas are compared with those that are protected from trawling, or only lightly trawled (Collie et al., 2000). Such differences can be found in all habitats if one looks hard enough, although it is equally clear that not all types of seabed are equally vulnerable. In view of the status of many fisheries and public concerns about the ecosystem, policy makers are now often charged with both managing fisheries more effectively and mitigating trawl impacts: in particular, they are facing increasing pressure to establish areas closed to trawling (Marine Protected Areas, MPAs). Responding to this pressure requires that the fishery manager address two fundamental issues. First, the objective for the closure must be specified: being quite clear about the underlying rationale for any policy measure is a pre-requisite for rational management. Second, the manager needs to be satisfied that the proposed measure stands a good chance of meeting the objective. For many aspects of the trawl impact and MPA debate, addressing these two issues is by no means straightforward.

Coastal systems and low-lying areas

Abstract: Since the IPCC Third Assessment Report (TAR), our understanding of the implications of climate change for coastal systems and low-lying areas (henceforth referred to as ‘coasts’) has increased substantially and six important policy-relevant messages have emerged. Coasts are experiencing the adverse consequences of hazards related to climate and sea level (very high confidence). Coasts are highly vulnerable to extreme events, such as storms, which impose substantial costs on coastal societies [6.2.1, 6.2.2, 6.5.2]. Annually, about 120 million people are exposed to tropical cyclone hazards, which killed 250,000 people from 1980 to 2000 [6.5.2]. Through the 20th century, global rise of sea level contributed to increased coastal inundation, erosion and ecosystem losses, but with considerable local and regional variation due to other factors [6.2.5, 6.4.1]. Late 20th century effects of rising temperature include loss of sea ice, thawing of permafrost and associated coastal retreat, and more frequent coral bleaching and mortality [6.2.5]. Coasts will be exposed to increasing risks, including coastal erosion, over coming decades due to climate change and sea-level rise (very high confidence). Anticipated climate-related changes include: an accelerated rise in sea level of up to 0.6 m or more by 2100; a further rise in sea surface temperatures by up to 3°C; an intensification of tropical and extratropical cyclones; larger extreme waves and storm surges; altered precipitation/run-off; and ocean acidification [6.3.2]. These phenomena will vary considerably at regional and local scales, but the impacts are virtually certain to be overwhelmingly negative [6.4, 6.5.3].

Critical science gaps impede use of no-take fishery reserves

Abstract: As well as serving valuable biodiversity conservation roles, functioning no-take fishery reserves protect a portion of the fishery stock as insurance against future overfishing. So long as there is adequate compliance by the fishing community, it is likely that they will also sustain and even enhance fishery yields in the surrounding area. However, there are significant gaps in scientific knowledge that must be filled if no-take reserves are to be used effectively as fishery management tools. Unfortunately, these gaps are being glossed over by some uncritical advocacy. Here, we review the science, identify the most crucial gaps, and suggest ways to fill them, so that a promising management tool can help meet the growing challenges faced by coastal marine fisheries.

Designing marine reserve networks for both conservation and fisheries management

Abstract: Marine protected areas (MPAs) that exclude fishing have been shown repeatedly to enhance the abundance, size, and diversity of species. These benefits, however, mean little to most marine species, because individual protected areas typically are small. To meet the larger-scale conservation challenges facing ocean ecosystems, several nations are expanding the benefits of individual protected areas by building networks of protected areas. Doing so successfully requires a detailed understanding of the ecological and physical characteristics of ocean ecosystems and the responses of humans to spatial closures. There has been enormous scientific interest in these topics, and frameworks for the design of MPA networks for meeting conservation and fishery management goals are emerging. Persistent in the literature is the perception of an inherent tradeoff between achieving conservation and fishery goals. Through a synthetic analysis across these conservation and bioeconomic studies, we construct guidelines for MPA network design that reduce or eliminate this tradeoff. We present size, spacing, location, and configuration guidelines for designing networks that simultaneously can enhance biological conservation and reduce fishery costs or even increase fishery yields and profits. Indeed, in some settings, a well-designed MPA network is critical to the optimal harvest strategy. When reserves benefit fisheries, the optimal area in reserves is moderately large (mode ≈30%). Assessing network design principals is limited currently by the absence of empirical data from large-scale networks. Emerging networks will soon rectify this constraint.

Overfishing of Inland Waters

Abstract: Inland waters have received only slight consideration in recent discussions of the global fisheries crisis, even though inland fisheries provide much-needed protein, jobs, and income, especially in poor rural communities of developing countries. Systematic overfishing of fresh waters is largely unrecognized because of weak reporting and because fishery declines take place within a complex of other pressures. Moreover, the ecosystem consequences of changes to the species, size, and trophic composition of fish assemblages are poorly understood. These complexities underlie the paradox that overexploitation of a fishery may not be marked by declines in total yield, even when individual species and long-term sustainability are highly threatened. Indeed, one of the symptoms of intense fishing in inland waters is the collapse of particular stocks even as overall fish production rises—a biodiversity crisis more than a fisheries crisis.

Documented and Potential Biological Impacts of Recreational Fishing: Insights for Management and Conservation

Abstract: While the impacts of high exploitation on fish populations and aquatic ecosystems are well-documented for commercial fishing, particularly in the marine environment, the potential biological impacts of angling received less attention. This paper discusses angling patterns within a framework of basic ecological and evolutionary literature and examines potential biological impacts of angling by focusing on study results associated with high exploitation rates and pronounced selective exploitation. The impacts range from impacts occurring directly on the exploited species (truncation of the natural age and size structure, depensatory mechanisms, loss of genetic variability, evolutionary changes), to those that occur on the aquatic ecosystem (changes in trophic cascades, trait-mediated effects). As a third category, impacts related to the angling activity per se are distinguished (habitat modifications, wildlife disturbance, nutrient inputs, loss of fishing gear). Although the main threats to fish often are l...