Zoogeography of the Oceans and Climate Change 3.pptx PDF

Marine Biology and Conservation Climate Change and Marine Lif The Evil Twin Part 3 BI2MBC1 Autumn 2024 Dr Graham Luk  CO2 – Green-house Gas and Ocean Acidifier When CO dissolves in water producing aqueous 2 CO2 (CO2(aq)...

Marine Biology and Conservation Climate Change and Marine Lif The Evil Twin Part 3 BI2MBC1 Autumn 2024 Dr Graham Luk  CO2 – Green-house Gas and Ocean Acidifier When CO dissolves in water producing aqueous 2 CO2 (CO2(aq)) it also forms carbonic acid in an equilibrium reaction (H2CO3) a) CO2(aq) + H2O ↔ H2CO3 (1) Carbonic acid rapidly dissociates to produce bicarbonate ions (HCO3-) b) H2CO3 ↔ HCO3- + H+ (2) which can also dissociate into carbonate ions (CO32-). c) HCO3- ↔ CO32- + H+ (3) b) and c) produce protons (H+) and thus lower pH pH Range of Ocean water - ~7.5 – 8.5 values i.e., the water is now more acidic. https://www.nature.com/scitable/knowledge/library/ocean- acidification-25822734 Global decline of 0.1 pH units, acidity rise of 26-30% The oceans have absorbed about 28% of the anthropogeni c CO2 produced over the last https://ocean.si.edu/ocean-life/invertebrates/ocean-acidification 250 years  What is the Effect of Ocean Acidification? Calcium carbonate (aragonite) is key structural / skeletal component in corals, many other marine invertebrates, and many planktons. Ocean acidification prevents/slows down aragonite creation (moves the 1 equilibrium of 1 to the right). Any physiological process involving carbonate chemistry and/or Calcium ions can be affected… https://ocean.si.edu/ocean-life/invertebrates/ocean-acidificati on  Calcium - a crucial for all metazoan life. It is vital for : Muscle activity, skeletal structures, blood clotting, wound-healing, nerve transmission and enzyme function. Acting as messengers in and between cells. It has thousands roles in cells, including cell migration, apoptosis, intracellular transport, and cell division. Fertilization, Population Level Effects Acidic conditions slows larval growth of sea urchins and mussels, meaning longer planktonic stages, and more exposure to predation and other agents of selection => fitness decline. (A) M. trossulus and (B) S. franciscanus. cidification is not universally harmful to marine life https://doi.org/10.2147/RRBS.S70357 “we predict increased growth and toxicity in harmful algal bloom species, and a significant increase in invasive algae in response to increased CO2 availability. Blooms of stinging jellyfish are also expected to increase since they are highly resilient to acidification. The effects of ocean acidification on invasive molluscs (eg, oyster drills), damaging echinoderms (eg, crown- of-thorns starfish), and a wide range of nuisance taxa will vary depending https://www.awi.de/en/about-us/service/press/press-release/ocean-acidification-stimulates-mass- on species and location.” Aragonite CaCO3 concentration (saturation) is lowered by acidic water. HCO ↔ CO + H 3 - 3 2- + CaCO3 Ca2+ Calcium ions bind to carbonate to form calcium carbonate (aragonite – coral skeleton) but Protons have greater affinity for carbonate ions than Calcium ions thus less CaCO3 is formed. pH lower along North Eastern US ote correlation with water Temp. This map shows aragonite saturation as projected in 2100. Regions in blue are values where corals and carbonate-shelled creatures can continue to grow. Regions in red are where the saturation levels are too low, and corals and shelled creatures will have a hard time building up their carbonate Summary A small change in the pH of seawater can have harmful effects on marine life, in numerous and inter-related ways. Building of Calcium based skeletons is particularly sensitive to acidity. If animals are able to build skeletons or complete other developmental processes in low pH water, more time and energy may be required to do so, diverting resources from other activities, and leaving them vulnerable to predation, with lower fitness and susceptible In to stress. combination with Temperature change and oxygen depletion, synergistic effects may exert considerable stress and fitness issues. Warming Seas, Oxygen Depletion, OceanAcidific ation A triple headed monster of acidification, sea temperature Climate Change, Warming Seas, and its Consequences Complex and multivariate relationships Affects all stages of life history, is massive in scope. This lecture – primarily metazoan – but also affects see flora and microbiota Phenology: The timing of a periodic biological phenomenon in relation to climatic conditions Why would the Red Cross / Red Crescent publish information briefings on Ocean Acidification?  Oceanic “Tropical coral reefs provide food Food and livelihood security for some 500 million people worldwide and Security – economists say that reefs support people to the value of 30 to 172 Socio- billion US dollars per year” Economics “….while the chemistry is predictable, the details of the biological impacts are not….. Beyond lost biodiversity, acidification will affect fisheries and aquaculture, threatening food security for millions of people, as well as tourism and other sea-related economies.” https://ocean.si.edu/ocean-life/invertebrates/ocean-acidification Fishing provides a huge amount of food to a growing world population, for some areas, it is the prime source of protein,  https://www.slideshare.net/jornw1/ocean-acidificati on-summary-for-policymakers-third-symposium-on- https://www.iucn.org/resources/issues- the-ocean-in-a-highco2-world briefs Laden with Information Fabulous experiment here is always a disaster movie……