Zoogeography of the Oceans and Climate Change PDF

Marine Biology and Conservation Zoogeography of the Oceans and Climate Change Part 1 Bristol Bay, Aleutian Islands - AlaskaBI2MBC1 Autumn 2024 Dr Graham Luk R...

Marine Biology and Conservation Zoogeography of the Oceans and Climate Change Part 1 Bristol Bay, Aleutian Islands - AlaskaBI2MBC1 Autumn 2024 Dr Graham Luk Review of lecture content on Mangroves, Coral Reefs, and Phytoplankton will be relevant to this lecture  Sea Surface Temperature (SST) Base period 1951-81 https://www.iucn.org/resources/issues-brief/ocean-warming https://www.theguardian.com/environment/2023/apr/26/accelerating-ocean-warming-earth-temper atures-climate-crisis  Water Column Temperature (WCT) Average change in heat content since 1955 2,000m to surface Total water column Blue region indicates 95% margin of uncertainty https://climate.nasa.gov/vital-signs/ocean-warming Ocean Warming - Consequences? Ocean warming affects fundamental physico-chemical properties of the ocean water Ocean warming evokes physiological and behavioural responses Ocean warming affects fundamental biochemical and physiological adaptations Ocean Warming - Consequences? Ocean warming affects fundamental Often3 physico-chemical properties of the complex, ocean water and Ocean warming evokes physiological multifact orial in and behavioural responses nature and Ocean warming affects fundamental relations hips biochemical and physiological adaptations Ocean warming affects fundamental physico-chemical properties of the ocean water. Dissolved Gases dissolveGasses. in liquids to form solutions. This is an equilibrium process (gas solution) affected by temperature and pressure. Ocean warming affects fundamental physico-chemical properties of the ocean water. Dissolved Gases dissolveGasses. in liquids to form solutions. This is an equilibrium process (gas solution) affected by temperature and pressure.  Physico-chemical properties of water – dissolved Oxygen Temperature Fresh Water ml/L Sea Water ml/L C 0 10.2 7.8 5 9.1 7.0 10 8.2 6.4 20 6.8 5.4 30 5.9 4.7 40 5.2 4.2 1 ml oxygen / 143g 1.4 ml/L (2mg/L) is considered Hypoxic of sea water o  Sea Warming Reduces Dissolved Oxygen Levels 2% decline global dissolved O2 content. Hot spots of 5%, with 7% predicted Warmer surface waters have less dissolved Oxygen. Warm water has low density and sinks. What does higher SST mean for O2  Behavioural Responses to Sea Warming Warming seas are causing population centres of fish to move, in part due to reduced Oxygen. For >70 N. Atlantic species “the bulk of their biomass has shifted … towards areas with cooler temperatures.” https://www.nefsc.noaa.gov/ecosys/spatial- analyses/ “North Sea winter bottom temperature has increased by 1·6 °C over 25 years, with a 1°C increase in 1988–1989 alone.” JAE, 2008; Demersal fish populations in the 45, 1029-1039 North Sea are changing latitude  Consequences of this? “….altered patterns of availability to local fishing communities, and possibly negative economic consequences as a result of https://www.nefsc.noaa.gov/ecosys/spatial-analyses/ lost access to stocks …. and rising fuel and travel costs.” Economic “…altered marine community structures …. some subtropical-temperate Ecological species may replace those species that are lost.” Some effects may be not so obvi “….shifts may also result in the concentration of targeted fish species increasing vulnerability to fishing activity. Atlantic cod, is one example..”  UK Marine Conservation Zones What will be the effects of these Zones? What might be the effect of rising sea Te https://www.mcsuk.org/press/mcz_round3_announcem https://www.wildlifetrusts.org/marine-protected- areas/england  UK Marine Conservation Zones What will be the effects of these Zones? What might be the effect of rising sea T “climate –smart fishing” https://www.bbc.co.uk/news/uk-politics-51289388 https://www.gov.uk/government/news/flagship-fisheries-bill- becomes-law https://www.wildlifetrusts.org/marine-protected- areas/england https://www.mcsuk.org/news/getting-climate-smart-our-new-  Physiological responses and their causes Biomolecular adaptation Enzymes have functional and optimal temperature ranges Human gut bacteria proteins are optimal at 37oC Thermal spring bacteria proteins are optimal around 70oC Thermal vent bacteria proteins are optimal around 90oC https://serc.carleton.edu/microbelife/extreme/extremeheat/yellows tone.html  Enzyme Temperature – Activity Curve Efficiency/Animal Activity Temperature All organisms have optimal body temperatures locked to their biochemistry and physiology. They thus have OPTIMAL ACTIVITY TEMPERATURES  Antarctica: an Unusual Continen Antartica – surrounded by clock-wise (outer) and anti- clockwise (inner) circumpolar currents. These contrary gyres ensure cooling polar waters are not diluted with warm waters.  Antarctica: an Unusual Continen Antartica – Sea water surrounded by commonly clock-wise (outer) -2oC around and anti- Antarctica clockwise (inner) Nototheniod continentalFish shelf circumpolar (Icefish) Restricted currents. almost exclusively to Antarctic - 120+ species Key adaptation for These contrary survival? gyres ensure cooling polar waters are not diluted with warm waters.  Antarctica: an Unusual Continen Antartica – Sea water surrounded by commonly clock-wise (outer) -2oC around and anti- Antarctica clockwise (inner) Nototheniod continentalFish shelf circumpolar (Icefish) Restricted currents. almost exclusively to Antarctic - 120+ species Key adaptation for These contrary survival? gyres ensure cooling polar waters are not diluted with warm waters.  Loss of Haemoglobin and then Myoglobin* Haemoglobin loss Myoglobin loss * Both are Oxygen binding protein s  Loss of Haemoglobin and then Myoglobin* Haemoglobin loss Myoglobin loss * Both are Oxygen binding protein HOW? s  Physico-chemical properties of water – dissolved Oxygen Temperature Fresh Water ml/L Sea Water ml/L C 0 10.2 7.8 5 9.1 7.0 10 8.2 6.4 20 6.8 5.4 30 5.9 4.7 40 5.2 4.2 “As the ability of sea water to hold oxygen increases with decreasing temperature, the oxygen concentration of the shelf water is exceptionally high, about 8 ml L− 1.”  Physiological responses and their causes Metabolic mismatch - the significance of the Q10 Q10 – a measure of the relative rate of reaction difference in a change of 10oC Simple chemical interactions/reactions respond in a linear manner to temperature increase. Many enzymatic reactions are temperature sensitive, but display a Q10 response. Metabolic processes included.  Metabolic Mismatch - the significance of the Q10 https://www.science.org/doi/10.1126/science.adf6035 “Between 2018 and 2021, after a period of historically high crab Starvation was one major factor: abundance and a series of marine Caloric requirements nearly double as heatwaves, the population of snow water temperature increases from 0° crab in the Bering Sea declined by to 3°C Metabolic mismatch Coupled with Oxygen Depletion “Even when not life- threatening, water deoxygenation has a range of negative effects on cod. For instance, the growth rate of cod starts to decline as soon as ambient oxygenation drops below 70% of full aeration. This is due to decreased food consumption caused by a reduced ability to cover the additional Pity the sessile organisms facing ocean warming