Showing results for: Fish and aquatic
Fish and other aquatic animals are an important source of food and protein for humans around the world. They are harvested in the wild (capture fishing) or cultivated in ponds or cages (aquaculture). Aquaculture now accounts for around 45% of total fish production while output from capture remains static. Fish and seafood confer many nutritional benefits: they are rich in protein, low in saturated fat, while oily fish and to a lesser extent shellfish are the main source of the essential omega-3 fatty acid DHA. Many aquatic species are now sources of pollutants in human food, with high levels of mercury and PCBs in animals high up the food chain. Overfishing, invasive species, and habitat destruction are responsible for widespread collapses of fish stocks. Overfishing also undermines the livelihoods of poor coastal communities who depend upon fishing for income and nutrition. Some fishing practices and aquaculture production systems can be highly energy intensive, meaning that fish from these sources can have a high GHG footprint.
Aquaculture generally supplements wild fisheries rather than replacing them, according to this paper, which used models based on historical data.
This paper assesses the possibility that cephalopods, such as squid, octopus and cuttlefish, could become a more important source of food in the future. In contrast to many fish population, cephalopod populations have been rising over the last few decades, possibly due to warmer ocean temperatures. The paper gives an overviews of the nutrients provided by cephalopods and the ways that they can be used as food. The authors also note that some cephalopods, including the octopus, are intelligent and possibly sentient, raising ethical issues over their use as food.
The vast majority of industrial fishing (defined as fishing vessels of over 24 metres) is done by vessels that are registered to relatively wealthy countries, according to a recent paper. Vessels registered to high income and upper middle income countries (according to World Bank classifications) accounted for 97% of industrial fishing effort in international waters and 78% of industrial fishing effort in the national waters of poorer countries. China, Taiwan, Japan, South Korea, and Spain together account for most of the fishing effort.
Farmed fish are often fed on forage fish (such as anchovies and sardines) caught from the wild. A new paper points out that demand for forage fish to support aquaculture production is forecast to grow beyond the maximum sustainable supply level. The authors calculate that demand for forage fish could be reduced to below the maximum supply limit by combining a number of measures: reducing use of forage fish in land-based agriculture, replacing some forage fish with fish trimmings from processing, and reducing the proportion of forage fish in the diets of non-carnivorous farmed fish.
The first systematic analysis of marine wilderness around the world finds that only 13% of the ocean can still be classed as wilderness, i.e. having experienced low impacts from human-caused stressors such as fertilizer runoff, fishing and climate change. Only 4.9% of that wilderness (covering 0.6% of total ocean area) falls within official marine protected areas.
The FAO has released its 2018 report on world fishery and aquaculture statistics. Key findings include that fisheries output peaked in 2016, having remained approximately static since the late 1980s, while aquaculture production is rising, as shown in the figure below. In 2015, fish accounted for around 17% of global animal protein consumption. One third of fish stocks are currently overfished, although progress has been made in the United States and Australia in increasing the proportion of fish stocks that are sustainably fished.
Scientists used DNA barcoding (testing a short section of the genome) to check whether fish in Metro Vancouver are really the species that they are labelled as being. They found that 25% of fish sampled were mislabelled, with error rates higher in restaurants than in grocery stores or sushi bars. Since the price of the claimed species was often higher than that of the real species, the paper suggests that some labelling may be intentional. However, the paper also suggests that some errors could be due to confusion between vernacular fish names (rather than scientific species names).
The World Wide Fund for Nature (WWF) hopes to use blockchain technology to make the entire seafood supply chain traceable. Working with tech startup TraSeable, fishing company Sea Quest and blockchain company Viant, WWF is running a pilot project to trace tuna through the supply chain by tagging catches with radio-frequency identification chips and QR codes - which can be scanned by a mobile phone.
Many important marine species, including marine mammals, sea turtles and seabirds, are threatened by bycatch - i.e. being accidentally caught by fishers who are targeting other species. A new paper finds that around half of the populations threatened by bycatch could be protected by managing fish stocks to maximise fishery profits, which would reduce bycatch as a side-effect of reducing overfishing.
This book, edited by Faisal I. Hai, Chettiyappan Visvanathan and Ramaraj Boopathy, discusses the social, economic and environmental sustainability implications of various aquaculture practices.
Building UK fish stocks up to their maximum sustainable yields could increase fish catches by 27%, create 5,100 new jobs and add £319 million to the UK’s GDP, NGO Oceana reports. Oceana points out that Brexit may provide a window of opportunity to change the UK’s fishing practices for the better.
Start-up Wild Type have raised $3.5 million towards the development of a platform and set of technologies that they hope could allow any type of meat to be cultured in the laboratory.
This paper presents the findings of a large-scale study which used global tracking data on sea-going vessels to characterise the scale, distribution and drivers of the global fishing effort.
Fish are generally seen as more efficient in converting feed into food than land-based species, but, according to a new paper, this conclusion does not hold if the retention of protein and calories is accounted for using a different measure.
Finless Foods hopes to make laboratory-cultured bluefin tuna the same price as the conventional product by the end of next year (bluefin tuna, threatened by overfishing, can sell for around $380/lb).
This blog by researchers Cedric Simon and Ha Truong from CSIRO Agriculture & Food discusses a method they have developed to reduce the amount of wild fish needed for prawn feed.