Marine Ecosystems and Climate Change Melissa Chin WWF-Malaysia RECSAM Seminar "Climate Change Scenarios and its Implication on Ecosystem and Biodiversity, Food Security and Health" 23 to 24 June 2009
Overview • According to the IPCC 4th Assessment report (2007), • "Warming of the climate system is unequivocal." • Observed increase in global average temperatures is very likely due to increase in anthropogenic GHG concentrations. • By 2100, • temperatures could increase by 1.1°C – 6.4°C • sea levels may rise by 18 to 59 cm. • Recent studies (Naturegeoscience & Science) suggests sea level rise could be at 80 to 200 cm
Oceans as Carbon Sinks Source: http://earthobservatory.nasa.gov/Library/CarbonCycle/carbon_cycle4.html
Threats to the Marine Environment • The BIG FIVE • Climate Change • Pollution • Invasive Species • Overharvesting • Habitat Loss
Warm and Acidic Seas Impacts on • Phytoplankton and zooplankton • Tropical and cold water corals • Mangroves • Marine turtles • Benthic, demersal and pelagic fishes
The Ocean Conveyor Belt Source: UNEP (2008). In Dead Water
Dead zones • Climate change may potentially reduce the intensity and frequency of the coastal flushing mechanisms, particularly at lower to medium latitudes over the next 100 years, which in turn will impact both nutrient and larval transport and increase the risk of pollution and dead zones. • Increased development, coastal pollution and climate change impacts on ocean currents will accelerate the spreading of marine dead zones. • The number of dead zones (hypoxic or oxygen deficient areas) increased from 149 in 2003 to over 200 in 2006. Most dead zones (a few are natural), have been observed in coastal waters, which are also home to the primary fishing grounds.
Ocean Acidification • Over the past 200 years, oceans have absorbed 1/4 of the CO2 produced from human activities. • This has caused the oceans (which are on average slightly alkaline) to become more acidic. • Average pH of oceanic surface waters has decreased by 0.1 units since pre-industrial times i.e. 30% increase in hydrogen ion activity. • Global atmospheric CO2 concentrations are now at 387 ppm. If current trends continue, CO2 concentrations will more than double pre-industrial levels by 2050 and the oceans will be more acidic than they have been for tens of millions of years. 13
Ocean Acidification • Hydrogen ions attack carbonate ions which are needed by marine organisms, such as corals and shellfish, to produce their skeletons, shells and other hard structures. • Carbonate ion concentrations are now lower than at any other time during the last 800 000 years • At CO2 concentrations 550 ppm, coral reefs may be dissolving globally. • By 2100, it has been estimated that 70% of coral reefs will be in waters unfavourable for growth.
Ocean Acidification • In the polar regions, model projections using current CO2 emission rates suggest that by 2060, 80% of waters will be corrosive to Arctic calcifiers such as pteropods, and bivalves such as clams, which play a key role in Arctic food webs. • Many coastal animals and groups of phytoplankton and zooplankton may be directly affected with implications for fish, marine mammals and the other groups that depend on them for food. • Ocean acidification is irreversible!
Invasive Species Source: UNEP (2008). In Dead Water
Coral Reefs Distribution of cold water and tropical coral reefs Source: UNEP (2008). In Dead Water
When Things Heat Up… • Corals live in symbiosis with zooxanthellae Stress (high temperatures, disease, pollution)
Phytoplankton & Zooplankton • Planktons play a central role in the global carbon, oxygen, and nutrient cycles • Climate impacts are, • Species with calcareous shells such as coccolithophores, echinoderms, crustraceans and molluscs may decline in abundance • Changes in phytoplankton and zooplankton abundance, distribution, composition and timing of production – likely to drastically impact most marine life • Likely alteration of environmental conditions that affect the occurrence of harmful algal blooms
Mangroves • Mangroves act as an important buffer between land and sea, filtering terrestrial discharge, decreasing sediment loading of coastal waters and maintaining the integrity of coastlines. • They play a vital role in nutrient and carbon cycling. • Mangroves act as a nursery and breeding habitat for marine species such as fish, crabs and prawns. • Climate impacts include, • Shift in species distributions with rising temperatures • Alteration to growth rates and survival with changes in rainfall pattern and abundance • Destruction of mangroves with sea level rise and enhanced frequency or intensity of storms
Seagrass Beds • Seagrass beds play a vital role in nutrient and carbon cycling and act as a buffer between the land and the sea. • Seagrass beds are important habitat for many species of fish and crustaceans as well as endangered species such as green turtles and dugongs. • Projected climate impacts: • Shifts in species distribution and alteration of species composition of seagrass beds as temperatures warm • Alteration of frequency and timing of flower and seed production • Increase in seagrass bed destruction if storm regimes become more frequent or severe
Fisheries • Changes in temperatures, current patterns, and primary and secondary production may affect larval fish health and transport • Changes in abundance of particular species in local regions • Climate change impacts will potentially combine with other fishery impacts to exacerbate further depletion of fish stocks
Marine Turtles • Skewed sex ratio towards females • Climate-induced alteration of food supplies will impact turtle populations • Climate-related increases in wave energy and storm events may erode nesting beaches and reduce egg survival • Alteration of life cycle events e.g. observed changes in peak timing of egg laying by loggerhead turtles in Florida
In Jeopardy • 80% of world corals may die within decades, eliminating other species that rely on them for survival • 85% of Malaysian reefs are threatened by human activities - Reefs at Risk (2002) • By 2050, 95% of the Great Barrier Reef may be lost • Significant impact to local livelihoods – loss of fisheries and tourism
In Jeopardy • Over 65% of the world’s seagrass communities have been lost by land reclamation, eutrophication, disease and unsustainable fishing practices • Up to 80% of the worlds primary catch species are exploited beyond or close to their harvest capacity, and some productive seabeds have been partly or even extensively damaged over large areas of fishing grounds. • Wetlands and mangroves are also declining rapidly, typically by 50–90% in most regions in the past 4 decades
The Need to Adapt • Mitigation is of upmost importance (“prevention is better than cure”) • But climate change is already happening. Ecosystems need to withstand and adapt to changes. • Ecosystem resistance - ability to withstand disturbance/change and maintain normal function • Ecosystem resilience – ability to recover
The Need to Adapt • Promote sustainable fisheries • Ecosystem Based Fisheries Management (EBFM) • Live reef food fish trade • Establish marine protected areas (MPAs) • Well designed and well managed networks • Protect species and habitats • Reduce non-climate stressors • Pollution • Tourism • Unsustainable coastal development
Coral Triangle • Dubbed the “Amazon of the Oceans”, it is home to 76% of the world’s coral species and 50% of the world’s reef fish species. • The Coral Triangle Initiative (CTI) • proposed at the Asia-Pacific Economic Cooperation meeting in Australia in 2007. • endorsed at the UN Climate Change Conference in Bali • At the World Oceans Conference in May 2009, 6 leaders adopted a 10-year plan of action to safeguard vital marine and coastal living resources in the Coral Triangle.
The Coral Triangle • If carbon emissions are not cut by 25 percent to 40 percent by the year 2020, higher ocean temperatures could kill off vast marine ecosystems and half the fish in them • Commercial fishing in the area generates roughly USD 3 billion in annual income. The Coral Triangle is home to the world’s largest population of commercially-important tuna species, supplying 50% of global tuna production. • The Coral Triangle is home to 6 of the 7 species of marine turtles • Around 100 million people risk losing homes and livelihoods unless drastic steps are taken to protect the Coral Triangle
Marine Turtle Programme • Marine turtles are threatened with extinction due to • Consumption of turtle eggs • Bycatch - accidentally caught in fishing gear • poorly-planned coastal development • marine and nesting beach pollution • illegal trade of turtles and their parts • potential climate impacts • Loss of nesting sites • Coastal erosion • Rising sea levels • Reduced productive success • Unbalanced sex ratio in hatchlings
Egg = Life • Among the issues that needed to be addressed included the protection of beaches, better support for by-catch of sea turtles, turtle egg consumption and better coastal planning to help the turtles and communities that depend on the area’s resources. • Fisheries Department had launched the National Plan of Action for Conservation and Management of Sea Turtles in November last year • Egg = life Campaign • Those who sign up will pledge to • support laws that will ban the sale and consumption of turtle eggs throughout Malaysia • support the call for comprehensive and holistic Federal legislation to conserve marine turtles • never consume turtle eggs or trade in turtles or their parts.
How you can help • Who’s job is it? • Government • Local community • Fishers • Tourism sector • Tourists • Citizens
Take Home Points • Climate change will provide numerous changes in oceans. • Climate change will place substantial strain on the marine environment along with pollution, over-harvesting and unchecked coastal development. • A lack of good marine data, poor funding for ocean observations and an ‘out of sight – out of mind’ mentality may have led to greater environmental degradation in the sea than would have been allowed on land.
Take Home Points • Substantial resources need to be allocated to reducing climate and non-climate pressures. • Building resistance and resilience of marine ecosystems is essential in the conservation, protection and sustainable management efforts at all levels • Priority needs to be given to protecting substantial marine areas of ecological and economical importance
References & Further Readings Reef Managers Guide to Coral Bleaching http://www.coris.noaa.gov/activities/reef_managers_guide/ A Practical Guide to Good Practice: Managing Environmental Impacts in the Marine Recreation Sector http://www.coralreefalliance.org Status of Coral Reefs of the World: 2008 http://www.gcrmn.org/status2008.aspx
References & Further Readings In Dead Water: Merging of Climate Change with Pollution, Over-harvest and Infestations in the World’s Fishing Grounds www.unep.org/pdf/InDeadWater_LR.pdf Impacts of Climate Change on Australian Marine Life www.climatechange.gov.au/impacts/publications/pubs/marinelife-parta.pdf
References & Further Readings • ReefBase (www.reefbase.org) • Coral Reef Alliance-International Coral Reef Information Network Library (www.coralreefalliance.org) • Reef Check Malaysia(www.reefcheck.org.my) • NOAA’s Coral Reef Conservation Program (www.coralreef.noaa.gov) (www.coris.noaa.gov) • WWF-Malaysia (www.wwf.org.my)