Daryl Peter McPhee

The Impacts of Recreational Four-Wheel Driving on the Abundance of the Ghost Crab (Ocypode cordimanus) on a Subtropical Sandy Beach in SE Queensland

There is increasing concern regarding the impacts of recreational four-wheel driving (4WDing) on sandy beach environments. The ghost crab Ocypode cordimanus is a widely distributed Australian species that utilizes beaches and dunes for constructing burrows and for foraging. Comparisons of ghost crab abundances (using burrow counts) in areas “open” and “closed” to recreational 4WDing were conducted on exposed sandy beaches on North Stradbroke Island, off the coast of southeast Queensland. Beaches where recreational 4WD activity is present had significantly lower ghost crab abundances than beaches where it is absent. The most plausible reason for this difference in abundance is that ghost crabs are highly vulnerable to being crushed by beach traffic when feeding on the beach at night. To mitigate the impacts of recreational 4WDing on ghost crab population management intervention is needed. Possible changes to the management of recreational 4WD activity include the setting aside of areas free of recreational 4WD activity for the conservation of biodiversity, or a prohibition on driving on the beaches between dusk and dawn. There is also a need for a consistent and transparent approach in Queensland for quantifying and monitoring 4WD activity in sandy beach environments.

Adopting turtle excluder devices in Australia and the United States: What are the differences in technology transfer, promotion, and acceptance?

Turtle excluder devices (TEDs) are being trialed on a voluntary basis in many Australian prawn (shrimp) trawl fisheries to reduce sea turtle captures. Analysis of TED introductions into shrimp trawl fisheries of the United States provided major insights into why conflicts occurred between shrimpers, conservationists, and government agencies. A conflict over the introduction and subsequent regulation of TEDs occurred because the problem and the solution were perceived differently by the various stakeholders. Attempts to negotiate and mediate the conflict broke down, resulting in litigation against the U.S. government by conservationists and shrimpers. Litigation was not an efficient resolution to the sea turtle-TED-trawl conflict but it appears that litigation was the only remaining path of resolution once the issue became polarized. We review two major Australian trawl fisheries to identify any significant differences in circumstances that may affect TED acceptance. Australian trawl fisheries are structured differently and good communication occurs between industry and researchers. TEDs are being introduced as mature technology. Furthermore, bycatch issues are of increasing concern to all stakeholders. These factors, combined with insights derived from previous conflicts concerning TEDs in the United Stares, increase the possibilities that TEDs will be introduced to Australian fishers with better acceptance.

The Disappearance of Oyster Reefs from Eastern Australian Estuaries—Impact of Colonial Settlement or Mudworm Invasion?

Oysters have been harvested on the east coast of Australia for many thousands of years. Coastal Aboriginal communities used the extensive estuarine oyster resource and may have farmed oysters by establishing shell cultch beds in shallow areas of estuaries. The British colonization of Australia commenced in 1788 and oysters were initially used for food and production of lime. Concerns about unsustainable exploitation led to introduction of legislation that directed the oyster industry to aquaculture in 1884. Translocation of oyster stock for fattening, from New Zealand to Australian east coast estuaries, was encouraged. Here evidence is presented that this activity resulted in “mudworm disease” appearing in oyster farming estuaries on the Australian east coast between 1880 and 1900. The pandemic permanently destroyed natural sub-tidal oyster reefs and forced the oyster industry to adopt avoidance farming techniques including intertidal farming to cope with mudworm.

Aspects of the biology of the yabby Trypea australiensis (Dana) (Decapoda: Thalassinidea) and the potential of burrow counts as an indirect measure of population density

The thalassinidean shrimp Trypea australiensis(the yabby) commonly occurs on intertidal sandflats and subtidal regions of sheltered embayments and estuaries along the east coast of Australia and is harvested commercially and recreationally for use as bait by anglers. The potential for counts of burrow openings to provide a reliable indirect estimate of the abundance of yabbies was examined on intertidal sandflats on North Stradbroke Island (Queensland, Australia). The relationship between the number of burrow openings and the abundance of yabbies was generally poor and also varied significantly through time, casting doubt on previous estimates of abundance for this species based on unvalidated hole counts. Spatial and temporal variation in population density, the size at maturity and the reproductive period of the yabby were also assessed. Except for an initial peak in abundance as a result of recruitment, the density of yabbies was constant throughout the study but considerably less than that estimated from a previous study in the same area. Ovigerous females were recorded at 3 mm carapace length (CL) which is smaller than previously recorded for this species and thalassinideans in general. Small ovigerous females were found throughout the study, including the summer months, which is unusual for thalassinideans in the intertidal zone. It was hypothesised that in the intertidal zone, small female yabbies may be able to balance the metabolic demands of reproduction and respiration at higher temperatures than can larger females allowing them to reproduce in the warmer months.

Unprovoked Shark Bites: Are They Becoming More Prevalent?

An unprovoked shark bite is an extremely infrequent, but highly disturbing hazard for water sport participants in many parts of the world. Information was analysed on the total number of unprovoked shark bites between 1982 and 2011. In this period, unprovoked shark bite were recorded from 56 countries with 27 recording fatalities; however 84.5% occurred in only six countries - United States, Australia, South Africa, Brazil, Bahamas and Reunion Island. The three shark species commonly responsible for unprovoked bites are the white shark (Carcharodon carcharias), the tiger shark (Galeocerdo cuvier), and the bull shark (Carcharhinus leucas). Over the period examined, the total number of unprovoked shark bites and the number that were fatal increased in frequency. However, fatalities from unprovoked fatal shark bite still represented an infrequent hazard to people utilising the coastal zone for water-based leisure activities. The increase in unprovoked shark bite could not be explained entirely by increases in human population, and this article also concluded that changes in the population of relevant shark species were also unlikely to explain the increase. The paper concluded that both natural and anthropogenic factors may change the amount of spatial overlap between relevant shark species and areas of human use.

The role of expenditure studies in the (mis)allocation of access to fisheries resources in Australia

Economic benefits are often the main reasons put forward for changing fisheries access and allocation arrangements between commercial and recreational fishers. An analysis of several case studies in Australia identifies that the purported economic benefits from reallocating access to fisheries resources from commercial to recreational fishers are based on inappropriate approaches to economic valuation including the “revenues argument” and the “cumulative-value argument”. The allocating of fisheries resources (on an economic basis) in an area between recreational and commercial fishers should not be based on simple but erroneous comparisons between recreational fishing expenditure and the gross value of production of commercial fishing. Rather, it should be based on comparing the benefit of an extra fish, or extra few fish, to each sector. If one sector is found to have a higher benefit, a small change in access should be made in its favour and, if necessary, a further series of small changes until the extra benefit gained by that sector is equal to the benefit gained (or lost) by the competing sector. However, any allocation decisions should not just focus on economic issues, but should also consider the ecological impacts and social costs and benefits attributable to both fishing sectors.

Feral deer in the suburbs: An emerging issue for Australia?

Deer are not endemic to Australia, but were introduced for game and aesthetics between the early 18th and 20th centuries. Until recent decades, most deer descended from these introductions. Before the 1970s when deer numbers and distribution expanded dramatically, farming was a modest enterprise. With the collapse of farming in the 1990s, large numbers of deer were deliberately released and translocated. Feral numbers and herds have subsequently expanded, and are increasingly encroaching on urban areas. As a new issue in Australia, views toward feral deer are polarized and span “welcome guest” to “major pest.” The emerging urban deer issues need greater acknowledgment and strategic management. This will require more emphasis on raising awareness, engagement with stakeholders, and development of legislative instruments to provide better strategic management of urban deer. This article reviews the potential increase in urban deer in Australia, considers the associated issues, and provides recommendations for management.