Man and the Last Great Wilderness: Human Impact on the Deep Sea

The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods

Satisfaction with leisure trips : findings from Ghent, Belgium

Recently, studies have started analysing how people perceive their travel and how satisfied they are with it. This travel satisfaction - i.e., the mood during trips and the evaluation of these trips – can be affected by trip characteristics, such as the used travel mode and trip duration. In this study – analysing leisure trips of 1720 respondents living in the city of Ghent (Belgium) - we do not only look at the effect of trip characteristics on travel satisfaction, but also on the effects of travel-related attitudes and the residential location on travel satisfaction, both singly and each controlling for the other. The latter makes it possible to analyse whether people who live in their preferred neighbourhood based on travel preferences (e.g., car lovers living in suburban-type of neighbourhoods) are more satisfied than people who do not. Furthermore, this chapter also explores possible outcomes of travel satisfaction. It is possible that satisfying trips with a certain travel mode increase the chance of choosing that mode for future trips of the same kind, whether or not indirect through changes in attitudes. Repetitive positively or negatively perceived trips might also affect longer-term well-being, such as life satisfaction, both directly and indirectly through the performance of - and satisfaction with - activities at the destination of the trip. On the other hand, life satisfaction can also influence people’s satisfaction with short-term activity episodes, such as satisfaction with leisure trips and activities

Selectividad del arte de pesca del voraz de Tarifa

Species and size selectivity of the deep water longline traditionally used in commercial fishing of the black spot seabream (Pagellus bogaraveo) were studied in the Strait of Gibraltar with four sizes of hooks. Black spot seabream contributed up to 88% of the catch by number. Catch and by-catch rates differed for the different hooks and fishing trials. Significant differences in average fish length between all hooks, except in one case, were found. The comparison of two experimental fishing trials within 4 years indicates a displacement towards smaller sizes in the size frequency distributions. The results of this study show that the fishing gear can be size selective depending on hook size. The fitted selectivity models for each experiments were very different despite having two hooks in common. This is probably due to the very different catch size distributions in the two periods, which suggests that the population size structure changed significantly between 2000/2001 and 2004/2005