1. Vulnerability of coastal fisheries
Presented by
Morgan Pratchett
Acknowledge co-authors – Contributions of SPC and especially critical data made available through the ProcFish prgram

2. Authors
This presentation is based on Chapter 9 ‘Vulnerability of coastal fisheries in the tropical Pacific to climate change’ in the book Vulnerability of Tropical Pacific Fisheries and Aquaculture to Climate Change, edited by JD Bell, JE Johnson and AJ Hobday and published by SPC in 2011.
The authors of Chapter 9 are: Morgan Pratchett, Philip Munday, Nicholas Graham, Mecki Kronen, Silvia Pinca, Kim Friedman, Tom Brewer, Johann Bell, Shaun Wilson, Joshua Cinner, Jeff Kinch, Rebecca Lawton, Ashley Williams, Lindsay Chapman, Franck Magron and Arthur Webb

3. Coastal fisheries are critically important for food security throughout the Pacific, but also make a very important contribution to national economies and livlihoods.
Generally, industrial tuna fisheries are considered to be the mainstay of fisheries revenue and national economies in the Pacific, BUT WE HAVE UNDERESTIMATED THE ECONOMIC IMPORTANCE OF COASTAL FISHERIES. The key issue is that most of the fish and invertebrates harvested from nearshore environments are caught by individuals or family groups (using low technology fisheries) for immediate consumption.
At the same time coastal fisheries are probably more vulnerable to climate change than any other fisheries sectors.

4. Coastal Fisheries Production
Gillett 2009
The reported annual production from commercial components of coastal fisheries is only 45,000 tonnes, but this is a very small component of the actual coastal fisheries production, given the overwhelming importance of subsistence fisheries. From a variety of different sources (including SPC Socio-Economic Surveys) we estimated that subsistence catches from coastal environment yield 110,000 tonnes per year. It is also possible that subsistence catches are 30% higher than we currently suggest.
Bob Gillet (in his seminal assessment of local economic importance of different fisheries sectors) estimated contribution of commercial and subsistence coastal fisheries to Gross Domestic Product (GDP) of Pacific Island Countries and Territories (PICTs) is at least US$272 million, which is 30% higher than the combined contribution of locally-based offshore fishing fleets.

5. Diversity of coastal fisheries
Coastal fisheries are characterised by being highly diverse, partly due to the wide variety of fishing methods that are used to catch different fish and invertebrates.
Major differences in catch composition among countries, but overall catches are dominated by carnivorous species (Lethrinidae and Serranidae = sea breams and groupers), described in the book. There are however, a lot of different species being harvested (not only in terms of fishes, but also invertebrates).

6. Distinct fisheries sectors
In terms of understanding the effects of climate change on coastal fisheries, it was important to distinguish three distinct fisheries sectors
Demersal = bottom dwelling
Nearshore pelagic fishes
Invertebrates
Each of these groups of organisms are vulnerable to different components of cliimate change and must be treated separately. To then relate effects of climate change on fisheries production it was important to have fisheries data at the same level, which was not always available!

7. Demersal fish
Specific definitions for each of the distinct fisheries sectors, as well as detailed explanations about what we did and did not consider in this chapter are provided in the section 9.2 (starting page 495) in the “big book”
Demersal (or bottom-dwelling) fishes are harvested predominantly from coral reef or inter-reefal habitats, and the importance of habitat quality and quantity cannot be overstated.
It is obvious, but important to remember, no habitat then no fish (especially, if you are talking about coral reef fisheries).

8. Nearshore pelagic fish
Nearshore pelagic fishes are distinguished from demersal fishes, in that they are probably much less reliant on the coastal habitats, such as coral reefs. For example, tuna, mackeral, and other large pelagic fishes probably don’t care about how much coral we have on our reefs. Rather, they are attracted to areas of high productivity, which still may change if we have declines in current strength and therefore, declines in the strength of up-wellings.
Small pelagics not being fully utilised (valuable resource)

9. Invertebrates
Often when we talk about fisheries, there is an overwhelming on fish. We recognise however, that many invertebrates (e.g., sea cucumbers and trochus) are critically important in the Pacific. The effects of climate change on invertebrates will be very different to effects on fishes. Importantly, most marine invertebrates are very sensitive to changes in pH (or aragonite saturation) caused by ocean acidification.

10. Direct effects of climate changepH
The overall effects of climate change on fish and invertebrates can be divided into both direct and indirect effects. In term of direct effects, they key issue is how the animals will be affected by changing environmental conditions, especially projected increases in temperature (which will increase 3oC) throughout this century, and pH which will decline (more acidic) over the same period.
Temperature

11. Indirect effects of climate change
Seagrass area
Coral cover
The indirect effects of climate change on reef fishes relate primarily to changes in habitat. We have heard previously that the both corals reefs and many other coastal habitats are going to be negatively effected by climate change. For coral reefs, it is projected that there will be very large declines in

12. Effects of temperature
Growth (mg/week)
Maximum growth
28-30oC
Acanthochromis polyacanthus
Projected increase
3oC by 2100
Temperature (oC)

13. Effects of temperature
Declines in:
growth
lifespan
reproduction
Fewer &
smaller
fish
Growth (mg/week)
Maximum growth
28-30oC
Projected increase
3oC by 2100
Temperature (oC)

14. Effects of temperature
Normal spawning temperature

15. Effects of ocean acidification
Other organisms affected:
Trochus
Oysters
Sea cucumbers
Crustaceans
Fish
Source: Fine and Tchernov (2007)

16. Effects of habitat degradation
0.5
-0.5 -1
Macroalgae
Proportional change
Habitat
complexity
Coral cover
Time after extensive coral loss (years)

18. Effects of habitat degradation
0.5
-0.5 -1
Macroalgae
Proportional change
Habitat
complexity
Coral reef fishes
Coral cover
Time after extensive coral loss (years)

19. 65% decline in abundance and diversity of fish

20. Projected coastal fisheries production

21. Projected coastal fisheries production
Climate change will have the greatest effect on demersal fishes, reflecting the important effects of loss and degradation of critical coastal habitats. Up until 2035, these effects will be relatively minor, but very pronounced as we move toward the end of the century.
For near shore pelagic fishes, it is expected that fisheries productivity will also decline but much less so than for demersal fishes. Again, this is because we don’t expect that degradation of coastal habitats will have a major effect on these species. Of greatest concern is the potential decline in the productivity of near shore environments associated with weakening of the Southern Equatorial Current (SEC) and upwellings.
For invertebrates there may be important effects of climate change on important commercial species (such as sea cucumber) but any declines in fisheries productivity are likely to be offset by potential increases in the productivity of shallow, intertidal habitats.

22. Priority adaptations
Protect structural complexity and biological diversity of coral reefs, mangroves and sea grasses to sustain fisheries and maximize adaptation potential
Recognise ecological importance of specific fish (e.g. herbivorous fish on coral reefs), and ensure stocks of these species are sufficient to maintain key ecosystem functions
Climate change provides renewed incentive for effective implementation of Ecosystem Based Management. No fish = no fishery, no habitat = no fish.

23. Priority adaptations
Diversify coastal fisheries activities to target species and habitats that will be least affected, or favoured, by climate change
Build effects of climate change into fisheries management, particularly the need to maintain spawning stocks to overcome shocks of greater climate extremes
Small pelagics fishes are one fisheries resource that has the capacity to support increased exploitation. Also, skipjack

24. Conclusions
Coastal fisheries are critically important for both food security and livelihoods across the Pacific
Up until 2035, effects of climate change will probably be indiscernible against the backdrop of existing anthropogenic disturbances, but immediate action is required to minimize future effects of climate change on coastal fisheries  
Immediate action both to mitigate potentially devastating effects of severe climate change, but also effective management to reduce local stressors on these environments.

25. Conclusions
Improved data on catches are needed to predict and monitor the effects of climate change on coastal fisheries
Data needed:
subsistence fisheries catches
separate data for the 3 distinct fisheries (or even species)