Marine Discovery Centre Climate Change Fishing Change Understanding Climate Change in Victoria's Fisheries Climate Change Hot Spot Map The world’s climate is changing at an unprecedented rate Climate change may affect: Currents Environmental flows Extreme weather conditions Nutrient supply Ocean chemistry Ocean temperatures Rainfall Winds The impacts of these changes on world fisheries may present significant risks and new opportunities, particularly in “hot spot” areas across the globe. The south-eastern coast of Australia, including Victoria’s coastline, is a “hot spot” A hot spot is an area experiencing rapid change, i.e. sea surface temperature. Victoria’s Fisheries Victoria’s Fisheries are diverse and geographically extensive (Warm currents moving south warm water species entering Victoria) We have productive coastal, bay, inlet and freshwater fisheries where commercial, aquaculture and recreational fisheries occur. Key fisheries include species of abalone, aquarium finfish, Australian salmon, barramundi, black bream, blue mussel, calamari, eel, flathead, King George whiting, Murray cod, rock lobster, snapper, trout, and yabby. Some of the habitats which support these fisheries include bays & estuaries, beaches & dunes, kelp forests, mangroves & salt marshes, open water, rocky reefs and seagrass & mudflats. Fisheries Victoria has examined the linkages between priority species and changing environmental variables. Two examples are provided here with King George whiting & black bream. Investigate some of the key processes that are likely to influence the resilience of these stocks to climate change. Whilst these changes present a challenge, research suggests climate change will also see improved offshore fishing opportunities for recreational fishers in Victoria with a wide range of species on offer. Image: Bays &estuaries Image: Beaches & dunes Image: Kelp forests Image: Mangroves & salt marshes Image: Open water Image: Rocky reefs Image: Seagrass & mudflats King George whiting King George whiting: Importance King George whiting is an important recreational & commercial fishery in Victoria. King George whiting: Importance – Estimated commercial value King George whiting: Importance – Catch data King George whiting: Importance – Nutritional value Seafood is well known for its nutritional value being: low in kilojoules, high in readily digestible protein, low in saturated fat, high in good fats (such as omega 3’s and omega 6’s), low in cholesterol, high in vitamins A B E & D and high in minerals iodine and calcium. In fact seafood is the best natural source of Omega 3 oils which provide many health benefits particularly in the fight against coronary disease, high blood pressure, arthritis, asthma and depression. Grilled whiting with limoncello and oregano by Pete Evans from his book Fish published by Murdoch Books This is a very simple dish but with beautiful subtle flavours. It is particularly lovely with a side dish of roasted fennel. Ingredients (serves 4) 250 ml (1 cup) extra Virgin olive oil Grated zest and juice of 2 lemons, Plus 2 lemons to serve 1 bunch oregano 90 ml limoncello or other lemon liqueur 4 whole King George whiting Method Preheat oven to 180°C. Stir together the olive oil, lemon zest and juice in a saucepan and place over medium heat until nearly boiling. Pour into a large flat bowl, immediately add the oregano and limoncello and leave for 30 minutes. Add the whiting to the marinade and leave for 10 minutes. Heat your barbecue grill and cook the whiting until cooked through, basting with the marinade several times. Pour a little more marinade over the fish and serve with lemon quarters. King George whiting - Life Cycle Eggs and larvae are pelagic/floating and are transported by currents, feed on zooplankton Larvae settle in seagrass beds in sheltered bays and inlets Juveniles and adults move to deep seagrass patches and adjacent sand areas, feed on benthic/bottom dwelling crustaceans Adults reach maturity at 3 - 5 years and move to coastal spawning grounds associated with rocky reefs King George whiting Environment – Seagrass bed habitats Seagrass provides a habitat for King George whiting, providing shelter and a place to forage for food such as invertebrates. Environment – Medium temperature and storminess Seagrass habitat for King George whiting Environment – High temperature and storminess Reduced seagrass habitat for juvenile King George whiting Environment – Very High temperature and storminess Significant losses of seagrass habitat for juvenile King George whiting Projections CSIRO predicts that seagrass abundance and extent may decline in the future due to: sea-level rise increased storminess Warmer temperatures This may reduce the ability of King George whiting to complete their life cycle. Adaptation Fisheries Victoria is examining key seagrass regions in Port Phillip Bay to determine how important they are for juvenile King George whiting. From this work we aim to provide natural resource managers with advice on conserving important seagrass habitats to enhance King George whiting stock resilience to climate change. Black bream Black bream: Importance Black bream is an important recreational & commercial fishery in Victoria. Black bream: Importance – Estimated commercial value Black bream: Importance – Catch data Black bream: Importance – Nutritional value Seafood is well known for its nutritional value being: low in kilojoules, high in readily digestible protein, low in saturated fat, high in good fats (such as omega 3’s and omega 6’s), low in cholesterol, high in vitamins A B E & D and high in minerals iodine and calcium. In fact seafood is the best natural source of Omega 3 oils which provide many health benefits particularly in the fight against coronary disease, high blood pressure, arthritis, asthma and depression. Seafood parcels by Alex Giannuzzi (MDC Education Officer) from an old family recipe book This is a quick & tasty dish my Mum used to make when I was younger. My boys love it with a side serve of vegies. Ingredients (serves 4) 1 carrot, peeled 1 Celery stick 1 green shallot 4 (about 480g) thin black bream fillets 12 scallops Ground black pepper 20g (1 tbs) butter 150mls thin cream 1 lemon, juiced 2 tsp wholegrain mustard Method Preheat oven to 180°C. Cut carrot, celery and green shallot into very thin 5cm-long sticks. Divide vegetable sticks into 4 equal portions. Place black bream fillets on a board and place a vegetable portion on the end of each. Top with 3 scallops. Gently roll up fillets and place seam-side down on a baking tray lined with non-stick baking paper. Sprinkle with pepper. Bake in pre- heated oven for 15-20 minutes or until fish just flakes when tested with a fork. Meanwhile, melt butter in a saucepan. Add cream, lemon juice and mustard and stir until simmering. Simmer for 1 minute. To serve, place the fish parcels onto plates and spoon over the cream sauce. Black bream - Life Cycle Adults spawn in 15 - 28 Cwaters from spring to early summer Eggs float in the water column and hatch after 2 days Larvae remain in water column for ~ 1 month Juveniles and adults found throughout estuaries, feed on benthic/bottom dwelling invertebrates Adults reach maturity at 1 - 4 years and move upstream in sheltered estuaries to spawn Environment – Environmental flows & salt wedge formation Environment – Moderate rainfall Freshwater inflows create a salt wedge in the estuary, which is what black bream need to spawn successfully. (Freshwater is less dense than salty water) Moderate flows lead to salt wedge formation in the estuary Environment – Very low rainfall Extended periods of drought Environment – Very high rainfall High fresh water flows flush estuary and saltwedge is lost Projections CSIRO predicts that Victoria may receive less rainfall in the future and heavy rainfall events may be more intense. Water flow in the estuary resulting from these events may reduce the ability of black bream to complete their life cycle. Adaptation Fisheries Victoria is examining key black bream estuarine fisheries to determine suitable flow regimes. From this work we aim to provide catchment managers with advice on environmental flow requirements to enhance black bream resilience to climate change. New Opportunities Mahi Mahi (Coryphaena hippurus) & Cobia (Rachycentron canadum) Changing offshore currents on the east coast of Victoria may result in new offshore species entering our fisheries. The major current in this region (the East Australian Current) has strengthened by 20 per cent over the last 50 years and is likely to continue to strengthen by another 20 per cent by 2100. This is likely to result in more warm water sub-tropical species being encountered by Victorian anglers. In recent time Victorian anglers have reported catches of Cobia and Mahi Mahi in Victoria’s coastal waters. These are two highly valued recreational species normally encountered in the warmer waters of Queensland and New South Wales. Acknowledgment New Opportunities Illustrations: Paul Lennon for Fisheries Victoria Projections: © CSIRO (2007) based on mid-range emission scenario (A1B) http://climatechangeinaustralia.com.au/technical_report.php Life cycles: © South-Eastern Australia Program: Adaptation of fish and aquaculture sectors and fisheries management to climate change in South-Eastern Australia (2010) ‘Hot spot’ map: adapted from Hobday, A. J. and G. T. Pecl (in review). Identification of global marine hotspots: sentinels for change and vanguards for adaptation. Proceedings of the National Academy of Sciences.