Oceans Management and Conservation Revision Notes PDF

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Oceans Management and ConservationRevision Notes1. Oceans and HumanityThe government advises we only eat 2 portions of fish a week.The ocean is vast and covers 70% if the earth’s surface and provides over 90% of habitable space.The Ocean is responsible for regulating our climate. It is responsible f...

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Oceans Management and Conservation Revision Notes 1. Oceans and Humanity The government advises we only eat 2 portions of fish a week. The ocean is vast and covers 70% if the earth’s surface and provides over 90% of habitable space. The Ocean is responsible for regulating our climate. It is responsible for around 90% of increase of heat content of the earth system from 1955-1998 (Levitus et al. 2005). Without the Ocean the Earth’s temperature would be over 70 degrees Celsius. Humans of the world are reliant on the Ocean for food – 3.1 billion people rely on fish for atleast 20% of daily protein intake. Some costal communities are more than 70% reliant.

Figure 1 – Costal communities with fish

Over half of the Oxygen that we breath comes from the oceans – phytoplankton and microscopic plants produce O2. The ocean also acts as a reservoir for CO2. The ocean provides industry that is worth trillions. Diving and snorkelling on Coral reefs alone generates 28 billion USD per annum. The global surfing industry is work 8 billion USD per annum (https://blogs.worldbank.org/voices/Sustainable-Tourism-Can-Drive-the-Blue-Economy ) “Blue mind” is a medically recognised effect which sees being close to the sea as being good for mental and physical health ( https://www.gov.uk/government/news/marine-and-coastal-areaslinked-with-better-health-and-well-being ). The ocean is however under threat – Overfishing, Pollution, warming, acidification, sea level rise, eutrophication, oil spills, invasive species, shipping strikes. SUMMARY Without the ocean life on Earth simply would not exist. The ocean absorbs vast amounts of heat and regulates the climate Phytoplankton in the ocean provides half the oxygen we breath The ocean is a crucial source of food, medicine, and enjoyment. Oceans are becoming increasingly threatened by Human Activity.

2. Global fisheries History of fishing -

Seafood has been a staple for over 160,00 years (mainly shellfish in the beginning) – shellfish do not move they get deposited post consumption First evidence of pelagic fishing was around 40,000 years ago and the earliest hook found in Okinawa is estimated to be 23,000 years old

Seafood availability influenced the dispersal patterns of early hominins throughout the world. Stocks of shellfish along the shores of the red sea provide a migration route out of Africa during periods of drought 7360-4790 years ago (https://www.york.ac.uk/news-andevents/news/2020/research/shellfish-migration-africa/ ) Hausmann, N., Meredith-Williams, M., Laurie, E., 2021. Shellfish resilience to prehistoric human consumption in the southern Red Sea: Variability in Conomurex fasciatus across time and space. Quaternary International, Coastal Prehistory and Submerged Landscapes: Molluscan Resources, Shell-Middens and Underwater Investigations 584, 20–32. https://doi.org/10.1016/j.quaint.2020.04.034 (Hausmann et al., 2021)

Figure 2 – Route out of Africa

Fish and seafood played a large role in manly early human civilisations. The roman invasion of Britain led to an increase in popularity of seafood amongst the British – although the Romans saw seafood as “uncivilised” and moved away from it.

Figure 3 Fishermen reflecting on catches of the time

Marine fisheries came about in the UK because of mismanagement of freshwater waterways (dams and pollution from farming during middle ages) – building of dams still causes destruction of fish stocks today. -

Early fisheries were fresh water due to Roman influence – as these fish were easier to catch than salt

Large seaworthy boats and increasingly efficient fishing methods (trawl nets) shifted fishing to the oceans. Demand for seafood increased with development of vast railways in the mid-19 th centuary to allow fish to be transported to inland cities and towns (https://www.theatlantic.com/science/archive/2019/05/medieval-people-were-already-ruiningfish/589837/ ) (Boissoneault, 2019) Boissoneault, L., 2019. The Medieval Practices That Reshaped Europe’s Fish [WWW Document]. The Atlantic. URL https://www.theatlantic.com/science/archive/2019/05/medieval-people-were-already-ruiningfish/589837/ (accessed 1.14.22). – Article saying that even 700 years ago there was concerns about depleting fish stocks with a king being worried for it

Thomas Huxley 1884 – Probably all the great sea-fisheries are inexhaustible; that is to say that nothing we do seriously affects the number of fish” -

In the 1880s boats gained steam power and fishing became industrialised At first catches seemed miraculous but over the 20th century this changed

The Effects of 118 years of industrial fishing on UK bottom trawl fisheries Thurstan, R.H., Brockington, S., Roberts, C.M., 2010. The effects of 118 years of industrial fishing on UK bottom trawl fisheries. Nature Communications 1, 15. https://doi.org/10.1038/ncomms1013 (Thurstan et al., 2010) Phase 1 – 1889 to world war one. There is a rapid industrialisation of fleets but a decline in Fish stocks Phase 2 – 1919 to 1939. Fleets begin to exploit the new grounds in Arctic and off the coast of Africa Phase 3 – 1956-1982 – distant stocks became depleted and access restricted Phase 4 – 1983 – 2007 – common fisheries policy – stocks are low but relatively stable

Figure 4 - Fish stock fluxations over last 118 years

Catch per unit effort is a common unit used for comparing fish takings WW1 and WW2 were unique in the sense it was a time where no fishing occurred and we saw stocks replenish after a prolonged period of no fishing. -

1960 saw a peak in catches and a crash after this – Human populations boomed around this time and production of everything was upscaled which led to overfishing Modern tech allowed for new places to be fished and fish stocks decline world-wide 1980 saw a type of stabilisation due to the common fisheries policy (stocks low but relatively stable)

Figure 5 - Status of World fisheries - http://www.fao.org/state-of-fisheries-aquaculture

Key facts from above article -

Global fish production reached 179 million tonnes in 2018 (156 million tonnes for human consumption) Since 1990 there has been a 14% rise in capture fisheries, 524% rise in aquaculture, 122% rise in total fish consumption However, in 1990 we saw 90% of fish stocks being considered sustainable but by 2017 only 65.8% are seen as sustainable Around 34% of fish stocks have been overfished Although 78.7% of all landings of marine fisheries come from biologically sustainable stocks.

Figure 6 - http://www.seaaroundus.org/fact-sheet/ Seas Around us project in Canada - This graph shows how accurate FAO is likely to be (FAO have underestimated catches by 50% since 1990) - Global catch has been declining since a peak in 1996. Black line is the estimated real catch number.

Ecosystem Changes Howarth et al (2014) https://onlinelibrary.wiley.com/doi/full/10.1111/faf.12041 Bycatches are causing a real issue -

This is the catchment of unwanted sea creatures Above article illustrates the amount of bycatches using a case study from longline fishery for mahi-mahi in the eastern pacific (43,000 fish hooks) Bycatches included endangered fish species like swordfish, crocodile, striped marlin are more

Habitat damage -

Trawling and scallop dredging is causing serious issues (see figure 7)

Figure 7 - Trawled vs Untrawled

Illegal Fishing https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0004570 Agnew, D.J., Pearce, J., Pramod, G., Peatman, T., Watson, R., Beddington, J.R., Pitcher, T.J., 2009. Estimating the Worldwide Extent of Illegal Fishing. PLOS ONE 4, e4570. https://doi.org/10.1371/journal.pone.0004570 (Agnew et al., 2009)

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This accounts for roughly 11 – 26 million tonnes per annum – a whopping quarter of global catch Often occurs in developing countries with poor enforcement and management where fish is important for subsistence Often associated with other criminal activities such as modern day slavery, transport of drugs and guns and other contraband

Issues in the media with Pseudoscience Worm et al (2006) Impacts of biodiversity loss on ocean ecosystem services. Science 314: 787-790. Will the world run out of fish by 2048? – no this was based on an absurd extrapolation – this article saw over 5000 citations and atleast 16 direct response articles

Even made it to seaspiracy. Worm wrote a follow up paper which contradicted his initial paper, admitting that the situation in the ocean is not as bad as previous stated. – this was a colab paper with his critics Worm, B., Hilborn, R., Baum, J.K., Branch, T.A., Collie, J.S., Costello, C., Fogarty, M.J., Fulton, E.A., Hutchings, J.A., Jennings, S., Jensen, O.P., Lotze, H.K., Mace, P.M., McClanahan, T.R., Minto, C., Palumbi, S.R., Parma, A.M., Ricard, D., Rosenberg, A.A., Watson, R., Zeller, D., 2009. Rebuilding Global Fisheries. Science. https://doi.org/10.1126/science.1173146 (Worm et al., 2009)

3. Fisheries Management Fisheries management is about the management of people, not fish. To ensure we do not run out of fish: -

Improve our scientific understanding of the oceans Reduce number of fishing boats Increase coverage of MPAs Enforce regulations more strictly Give more controls to fishermen over how to manage their own stocks

Tragedy of the Commons ‘Fisheries provide the classic example of the tragedy of the commons, which occurs when property rights are incomplete and access to a resource is open. The migratory nature of most fish species makes it difficult to establish and protect rights to fish in the sea, so the rule of capture prevails. The result is often overexploitation of the resource.’ Daniel K. Benjamin https://www.econlib.org/library/Enc/TragedyoftheCommons.html

Maximum Sustainable Yield (MSY) -

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This is the largest average catch that can be captured from a stock under existing environmental conditions. MSY aims at a balance between too much and too little harvest to keep the population at some intermediate abundance with a maximum replacement rate. The idea is to keep populations at an intermediate level (about half carrying capacity) because at this point fish are able to breed at their maximum rates – Its like earning interest on a savings account This is dependent on maximum number of surplus fish to be caught This occurs at between 30 and 50 % of the biomass of an unexploited stock

Figure 8 - What fishing does to fish stocks – Biomass can be replaced with fish population density and mean body size and the same figure would apply.

Figure 9 – Graphical representation of MSY and areas of overfishing

MEY – Maximum economic yield This overlaps with the MSY are is lower than MSY. It creates fewer jobs and leaves fish in the oceans due to it being more efficient and precautionary. Fishing costs increase as yield decreases at a certain point

. Figure 10 - MSY vs MEY in economic context

The recipe for success -

Accurately estimate the size of fish populations (how they vary in time and space) & understand their biology Set limits on fishing in line with science (precautionary approach)

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Ensure the rules are respected (enforcement) Protect the functionality of the wider ecosystem (ecosystem approach)

Charles Shepard – Managing fisheries is hard: its like managing a forest, in which the trees are invisible and keep moving around. How fish are counted Mainly via fishing. Trawling surveys, underwater video, SCUBA diving, acoustic surveys etc. All methods have pros and cons and are better suited to some species than others – no methods are 100% accurate A good knowledge of fish biology is required – age, growth, movement, breeding patterns etc… -

Certain fish over 100 years old – fished to almost extinction

Regulation of fishing – Catch vs Effort control Catch control – limit the amount of fish caught via quotas + highly directed at target species - bycatch, discarding and monopolisation of quotas Effort control – limit the among of fishing (number of boats, size, fishing time and gear) -

+ simple, everything can be landed Imprecise, hard to control, does not account for a species vulnerability

Usually, a combination of approaches works best.

Figure 11 – Graphical representation of how much quotas set by politicians exceed recommended levels set by scientists.

eary, BC, Smart, JCR, Neale, FC, Hawkins, JP, Newman, S, Milman, AC & Roberts, CM 2011, 'Fisheries mismanagement', Marine pollution bulletin, vol. 62, no. 12, pp. 26422648. https://doi.org/10.1016/j.marpolbul.2011.09.032

Illegal, Unregulated and Unreported fishing (IUU) -

Global losses from IUU fishing are between $10 and $23.5 billion USD per year Total catches between 11 and 25 million tonnes per year This equates to approximately 20% of the global fish catch – 50% in some areas! Strong link with weak governance i.e 40% of catch in West Africa is illegal Often linked to human rights abuses, drug trafficking and illegal trade in wildlife

Figure 12 - Graphic of illegal catch vs reported catch (estimate)

Science Partnerships https://www.sciencedirect.com/science/article/abs/pii/S0308597X21002979 Ford, E., Stewart, B.D., 2021. Searching for a bridge over troubled waters: An exploratory analysis of trust in United Kingdom fisheries management. Marine Policy 132, 104686. https://doi.org/10.1016/j.marpol.2021.104686 (Ford and Stewart, 2021) Studies have show than there is low trust in science and management by fishermen. Fishermen that had worked with scientists had a much higher level of trust Fishermen and fishing boats are an incredible source of knowledge and data – fishermen and scientists need to work together more. It is assumed that a better respect of management measures would likely follow Ecosystem Approach Single species fisheries management rarely works. Managers need to consider the effects on the wider environment Complex habitats are often crucial nursery and feeding areas. Disruption of food webs can effect both other fishers and other sectors

Reduction of ecosystem effects -

Protect sensitive habitats MPAs Develop more selective fishing gear Protect vulnerable species Use ecosystem models to predict food web effects and manage accordingly

4. Aquaculture Who has the right to fish? ‘In 1215, the barons forced King John to sign Magna Carta at Runnymede because he had been selling monopolies over common resources such as fishing. Magna Carta acknowledged that there was a right to fish, to have passage by sea and other matters.’ file:///C:/Users/curti/Downloads/Public%20Rights%20to%20fish%20JWL%202005%20(16%206).pdf – Public right to fish – is it fit for purpose? EU fight The European fisheries management scheme is the most complicated in the world. The North sea is bordered by 7 countries and Ireland to the west, Faroes and Iceland to the North. Most species are very mobile and move through multiple countries waters – mackeral, cod, haddock, herring, plaice Share management is still necessary post-brexit – most valuable sedemtary species are largely under UK control – scallops, crabs, lobsters. Figure 13 - Map representing borders of the North Sea

Giving fishermen more ownership of the resource Costello et all (2008) https://www.science.org/doi/10.1126/science.1159478

Figure 14 - Infographic comparing stocks that are managed with some form of a quota (dotted line) to non manged stocks (or non ownership management solid black line). Large dotted line shows fisheries that had implemented catch shares over time and this has been quite successful

A degree of control is somewhat good – figure 14 shows the sustainability of fisheries with part of fishermen ownership. More than half the value of England’s quotas of fish is foreign owned – quotas are ownded by foreign investors and are leased out to local companies for profit. https://unearthed.greenpeace.org/2018/10/11/fishing-quota-uk-defra-michael-gove /

AQUACULTURE Aquaculture – the cultivation of aquatic organisms (animals and plants) in controlled aquatic environments for any commercial, recreational or public purpose. -

The breeding, rearing and harvesting takes place in all types of water environments including ponds, rivers, lakes, the ocean and man-made “closed” systems on land. It is done to – produce food, rebuild populations of threatened and endangered species, restore habitats, enhance wild stocks, produce baitfish, and culture animals/plants for zoos/aquariums.

Mariculture – aquaculture done in marine environments. Aquaculture has a long history. Gunditijmara people of western Victoria developed sophisticated channels, traps and holding ponds for eels dating back 6500 years. Farming carp in china though to have started around 1000BC Ancient romans farmed oysters and kept other species in ponds Very common in middle ages – mussel farming was invented in the 13 th century https://theconversation.com/the-detective-work-behind-the-budj-bim-eel-traps-world-heritage-bid71800 Facts and figures of Aquaculture •

The total production consisted of:

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82.1 million tonnes of aquatic animals

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32.4 million tonnes of aquatic algae

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26 000 tonnes of ornamental seashells and pearls.

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In 2018, inland aquaculture produced 51.3 million tonnes of aquatic animals, accounting for 62.5 percent of the world’s farmed food fish production. This refers to aquaculture produced either from inland natural water sources, such as rivers and lakes, and fish farms.

Figure 15 - Inforgraphic displaying the global rise in Aquaculture - 89% of which has taken place in Asia over the last two decades

Salmon Farms Atlantic Salmon is the most commonly farmed species in the UK – over 150,000 tonnes is produced per year from over 200 farms. The exports are worth over 119 mill per year (not correct figure “but not much more than that” Nicola Sturgeon wants to double production by 2030.

Issues Food sources -

The biomass conversion of salmon feed to salmon is inefficient Originally salmon were fed a high content of fishmeal and oil Most of this is sourced from “forage fish” – anchovies, sprats ect This has largely been replaced with vegetable products now But farmed salmon requires roughly 2-2.5 kg of fish to grow 1kg (although in wild 10kg is needed for 1kg of Growth)

Pollution -

Excess food and waste from Salmon farms is thought to pollute the surrounding area This can lead to deoxygenation and algal blooms

Disease & parasites -

High densities in farms promote disease and sea lice which requires chemical and antibiotic treatment (not good)

Unwanted effects on Wild Salmon -

Farmed salmon can spread disease to native populations Farmed stocks are selectively bred Escapes are common and interbreeding with wild populations will dilute the genetic integrity of wild stocks which are already under threat.

Effects on other species -

Seals pose a threat to salmon farming so are actively scared away

https://www.bbc.co.uk/news/uk-scotland-48266480

Offshore aquaculture -

Could be seen as robbing peter to pay paul. Disease and chemicals will see be released into the oceans Storms will be more intense and therefore escapes will be more common The effects may be spread over a wider area

Shellfish

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Farmed shellfish (oysters, mussels, clams and scallops) provide around 25% of the worlds seafood These species don’t need any supplemental feed, they filter water and absorb carbon in their shells – some say they are better than being vega...