Presentation on theme: "The Science of Marine Conservation: what we know, what we don't know (yet) and what we'll never know (Presentation to the Endeavour Society at Bangor University."— Presentation transcript:
The Science of Marine Conservation: what we know, what we don't know (yet) and what we'll never know (Presentation to the Endeavour Society at Bangor University on 27 th November 2008) Keith Hiscock
Main topics in the presentation Knowing what’s out there (biodiversity-wise) Knowing how to organize biodiversity information Knowing how marine ecosystems ‘work’ Knowing about and understanding change – natural and anthropogenic Knowing about recovery potential Explaining and predicting change – what we think we (might) know What we don’t know – what’s around the corner? For further reading, see reference lists in reports accessible on www.marlin.ac.uk/pap and www.ukmpas.org
We know that we have some fabulous marine life in UK waters Plymouth Drop-off, 30m
Heybridge Basin, Blackwater Estuary Yes, even in locations like this
We know how to organize information – classification of species and numbers See: www.marlin.ac.uk/PDF/MLTN_ biodiversity.pdf 8, 229 multicellular marine species listed in the Species Directory for Britain and Ireland Taxonomic tree from www.coastal.edu 35 major groups of organisms in the sea, 15 on land
Phymatolithon calcareum maerl beds with hydroids and echinoderms in deeper infralittoral clean gravel or coarse sand (Code: IGS.Phy.HEc). Image: Keith Hiscock We know how to organize information - marine habitats (biotopes) 262/370 biotopes (at Level 4/5) in the 2004 classification (Connor et al. 2004. See: www.jncc.gov.uk/page-1584)
And, we can classify them: The EUNIS biotopes classification EUNIS level EUNIS code EUNIS name 1AMarine habitats 2A1Littoral rock and other hard substrata 3A1.1High energy littoral rock 4A1.11Mytilus edulis and/or barnacle communities 5A1.113 Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock 6A1.1131 Semibalanus balanoides, Patella vulgata and Littorina spp. on exposed to moderately exposed or vertical sheltered eulittoral rock
We know about the distribution of species - much as they were 150 years ago Forbes, E. (1858). The Distribution of Marine Life, illustrated chiefly by Fishes & Molluscs & Radiata. In A.K. Johnston's Physical Atlas, pp. 99-101, Edinburgh
– the major physical, chemical and biological factors that ‘drive’ marine systems (essential to know for the ‘ecosystem approach’): From Hiscock et al. 2006. The structure and functioning of marine ecosystems: an environmental protection and management perspective. MarLIN report to English Nature. (Drawing: Keith Hiscock & Jack Sewell). Access from: www.marlin.ac.uk/pap. We know how marine ecosystems ‘work’:
And, what are the inputs and outputs Some physical, chemical and biological factors affecting a small marine habitat
We know - that many marine species have poor dispersal potential (important for understanding connectivity and networks): Mean dispersal distance estimates for marine benthic organisms. From: Kinlan, B. P., and S. D. Gaines. 2003. Propagule dispersal in marine and terrestrial environments: a community perspective. Ecology 84: 2007-2020.
Hunstanton beach after a storm We know - that ecosystems change, naturally
We know that some habitats and associated species are similar to historical descriptions The rocky subtidal communities at Hilsea Point Rock are very similar to those described over 50 years ago (Hiscock, 2005, JMBA 85, 1009- 1010)
We understand that small scale disturbance will be unlikely to change the biotope present and recovery is possible even from large scale disturbance We know: that disturbance can change ecosystems – sometimes ‘for ever’ but it may be difficult or impossible to facilitate reversal of effects of abnormal or very large scale disturbance
Extraction (aggregates) : substratum loss; smothering by sediment plume; loss of substratum stability. From Kenny & Rees, 1994. MPB 28, 442-447 See: Boyd, et al. 2004. Assessment of the rehabilitation of the seabed following marine aggregate dredging. CEFAS Technical report No. 121. We know that recovery can occur from human activities
Leigh, New Zealand: ‘Urchin barrens’ like this in 1976 Including through the establishment of Highly Protected Marine Reserves
But with protection predators not only become commoner, they also grow larger Image: Bill Ballantine
so now, kelp forest or turf Image: Tony Ayling See: Langlois, T.J. and Ballantine W.J. 2005. Marine ecological research in New Zealand: developing predictive models using no-take marine reserves. Conservation Biology 19:1763-1770.
The highly protected area at Lundy: increasing lobster stocks
Abundances of lobsters ANOVA tests: Year x NTZ vs Control: Non significant (F 3,3 = 0.19, P = 0.89) Year x NTZ vs Reference: Non significant (F 3,3 = 5.25, P = 0.10) NearFar
Areas closed to fishing can be beneficial to fisheries - spillout Closed Area I Haddock CPUE Lbs./hour fishing 0 lbs. 0.1-500 lbs. 501-1000 lbs 1001-3000 lbs. 3001-7500 lbs/hr Murawski, S. A., S. E. Wigley, M. J. Fogarty, P. J. Rago, and D. G. Mountain. 2005. Effort distribution and catch patterns adjacent to temperate MPAs. ICES Journal of Marine Science 62:1150-1167.
Partnership for Interdisciplinary Studies of Coastal Oceans. 2007. The Science of Marine Reserves (2nd Edition, International Version). www.piscoweb.org/outreach/pubs/reserves For a summary of benefits of marine reserves: 7
Some of what we know about impacts is obvious and does not need hypothesis driven, statistically robust, expensive, delaying, and distracting research Lyme Bay reefs: Devon Biodiversity Records Centre
Knowing about recovery potential - some species are unlikely to return if they are lost Species that are slow growing, have short-lived larvae and reproduce infrequently are unlikely to recover - ever Axinella dissimilis: growth rate <1mm a year
Some ‘for ever’ changes are obvious: Construction has built on or removed natural habitats forever. Non-native species have changed natural habitats and assemblages forever.
Fragile species with short-lived propagules and/or that are long-lived, slow growing and may recruit infrequently (including that are key biotopes components). For instance: Sunset coral. Larva short- lived, settles very near parent. Deep sponge biotope. Very slow-growing & long-lived component species ? (No colonisation of new surfaces). Fan mussel, Atrina fragilis. Very long-lived larva. Devastated by mobile fishing gear. Some species and biotopes we should protect now, identified by ‘Threat of significant decline’ criteria* * Defra, 2005. Review of Marine Conservation – Working Group report to Government. PB 9714. London, Department for Environment, Food and Rural Affairs. http://www.defra.gov.uk/wildlife- countryside/ewd/rmnc/pdf/rmnc-report-0704.pdf
Sensitivity is identified from the intolerance of a species or habitat to damage from an external factor and the time taken for its subsequent recovery. Including ‘recovery potential’ in assessing ‘sensitivity’ www.marlin.ac.uk
Data source: Met Office Hadley Centre Grid square 50-51ºN, 4-5ºW 11.0 11.5 12.0 12.5 13.0 13.5 190519251945196519852005 Year Mean annual SST (ºC) 11.0 11.5 12.0 12.5 13.0 13.5 190519251945196519852005 Year Mean annual SST (ºC) See also Sheppard, 2004, Mar. Poll. Bull., 49: 12-16 We know that climate change (especially warming) is happening
In the UK: southern species – advancers? Laminaria ochroleuca Paracentrotus lividus Eunicella verrucosa Anemonia viridis In the UK: northern species – retreaters? Alaria esculenta Strongylocentrotus droebachiensis Swiftia pallida Bolocera tuediae See Hiscock et al. 2004. Aquatic Conservation 14, 333-362. Which species will be winners or losers?
Unraveling interactions - fish populations have changed in abundance, size and species composition – climate or fishing? The MBA has maintained long-term data sets on fish populations since 1911. October 1963 November 2001 Sharpest declines seen in large species: skate & ray, brills, conger eel
Species declining with fishing Species correlated with more fishing Species increasing with warming Genner, Sims, Southward, & Hawkins, 2004, Proc. Roy. Soc., 271, 655-661. We think we know which species are being affected by warming v. fishing (No cold water species losses correlated with warming)
www.searchmesh.net We do not know ‘what is where’
And seabed maps are often wrong (The seabed west of Rame Head is predominantly rock, not fine sand)
We do not know why some changes (e.g. at Lundy) are occurring Lundy Knoll Pins 1986 Lundy Knoll Pins 2001
But we can make some informed guesses Seawater type : “ ….. the numbers of postlarval fish and of other species especially decapods were very abundant in the plankton off Plymouth in the 1920's, declined in the 1930's, and stayed low until somewhere around 1965 when a marked increase in the macroplankton, including fish larvae occurred. Abundance is high when water masses off Plymouth become of the ‘Sagitta elegans’ type. (Russell, 1973. JMBA 53, 347-355). Alan Southward, in the Cooper Memorial Lecture on 31 March 1998, suggested that what is now known as the ‘Russell Cycle’ returned to its 1920's peak between 1965 and 1979. The North Atlantic Oscillation may also be important. Elevated nutrients (perhaps working with warming events): Environment Agency (1999) in the State of the Environment’ report notes that nutrient levels in the Bristol Channel are elevated. Contaminants: in the case of severe contamination (for instance by TBT), species richness in enclosed areas can be halved (Rees et al. 2001. Mar. Poll. Bull. 42, 137-144.) Disease: certainly the case for conspicuous mortality in sea fans (Vibrio splendidans – or something like it - did it), but was anything else affected? And, is likelihood of disease exacerbated by high nutrient levels? Seawater fertility: “… the difference in bottom fauna from one region to another may be related to the ability, or otherwise, of larval stages to develop in the overlying water mass. (Wilson, 1951. JMBA 30, 1-19) Natural cycles or events? Disease? Contamination via human activities? Toxic phytoplankton? The non-native dinoflagellate alga Karenia mikimotoi (previously Gymnodinium aureolum) is now very widespread and is known to be responsible for mass mortalities of benthic species – does it have a sublethal or low-level mortality effect that may reduce resistance and vigour?
What we don’t know – what’s around the corner? Fish and invertebrates killed by a bloom of the non-native dinoflagellate alga Karenia mikimotoi (previously Gymnodinium aureolum) in Killary Harbour in July 2005. Image: Rohan Holt. A red tide Another non-native species – probably the next nasty surprise
What we don’t know – importance of biodiversity for ecosystem functioning (and the supply of goods and services) Research requirements identified via the UK Biodiversity Research Action Group (BRAG) at the initiative of Defra and the Joint Nature Conservation Committee (report awaited) – but a whole separate lecture! Functioning. The mode of action by which the system fulfils its purpose or role, as determined by its component elements. In terms of ecosystem functioning; the activities, processes or properties of ecosystems that are influenced by its biota (Naeem et al., 2004). Naeem, S., Loreau, M., & Inchausti, P., 2004. Biodiversity and ecosystem functioning: the emergence of a synthetic ecological framework. In: Biodiversity and Ecosystem Functioning (ed. S. Loreau, S. Naeem & P. Inchausti), pp. 3-11. Oxford: Oxford University Press.
What we’ll never know Enough! to predict, with precision, the consequences of human activities on marine habitats and species and the likely prospects for recovery to what extent; to understand the role of all of the species in a habitat for ecosystem functioning; to anticipate the character and scale of natural fluctuations; to separate with absolute certainty the effects of human activities from natural change. So, the easy questions are answered, and the difficult ones are left for you to solve.
you and your children will still be able to see this We still have lots of fabulous marine life and, with political action, good will and good luck, www.mba.ac.uk