We are proud to present you the three plenary speakers at IPFC (Valeriano Parravicini, Gerard Closs, and Daniel Pauly) and the two winners of Bleeker awards (David Bellwood and Keiichi Matsuura). These researchers will give a plenary talk (around 30 min) in the main amphitheatre of conference venue during the IPFC. The schedule of their presentation will be decided early in September.
Functional biogeography of reef fishes
The traditional goal of biogeography is the analysis of species distribution, which grounds it in the taxonomic classification of biodiversity. However, functional approaches that focus on species traits instead of species are emerging as a powerful tool for understanding ecosystem functioning. The field of functional biogeography recently leaped forward thanks to our increased ability to characterize relevant traits for a large number of species. It has hence been proved to be an important approach to the interpretation of biogeographical patterns and a useful tool for the prediction of the consequences of global changes. In this talk I will present how functional biogeography of reef fishes provides new insights on our understanding of the functioning of coral reefs and on their vulnerability to ongoing global changes. The global gradients in the functional organization of reef fish assemblages reveal that today-patterns are likely shaped by the interaction of species body size and geographical isolation across evolutionary time scale. Small species (i.e. <15 cm) appear to be dominant in continental, species-rich locations where coral reef habitat was not severely affected by past climatic oscillations. Conversely, large species (i.e. >30 cm) are dominant in depauperate, insular locations characterized by high climatic instability and isolation. Such global variation in the size-spectrum of fish assemblages likely corresponds to a parallel gradient in the food-web organization, where species-rich assemblages may be particularly vulnerable to coral loss and even the extremely high richness of these assemblages may not be enough to guarantee the desired redundancy of functions.
Larvae and Landscape: Life history, migration and dispersal in diadromous fish
Most species of fish, be they marine or freshwater, have small pelagic larvae. In species with a benthic adult life history stage, these benthic-pelagic life history migrations are well recognised from both marine and freshwater systems. Somewhat paradoxically, and despite the success of this life history strategy, tiny pelagic larvae are fragile, often dying en masse when confronted by harsh conditions. So why do so many fish exploit this apparently vulnerable life history strategy. The answer to this paradox appears to be fecundity – tiny eggs and larvae that when reared in a suitably productive and benign pelagic environment, generates prodigious recruitment back into adult habitat. Such reproductive success can facilitate the dominance of these highly fecund species in and around marine and freshwater pelagic environments. However, when this life history strategy is unavailable, less fecund life histories can persist, with large robust larvae required to survive challenging larval rearing conditions.
Diadromous migrations in freshwater fish species – specifically amphidromy and catadromy – can be viewed as strategies for getting large numbers of larvae into pelagic rearing environments, and so gaining the fecundity advantage that comes from producing tiny eggs and larvae. The distribution of the two apparently different life histories can be understood as a response to the challenge of transporting fragile larvae from adult habitats to a pelagic rearing habitat across varying aquatic landscapes and hydrological environments. Multiple non-migratory freshwater species have also evolved from diadromous species across the Indo-Pacific. However, the evolution of a non-migratory freshwater life history strategy often comes at the cost of fecundity, as such species often require larger robust larvae to survive in unproductive headwater stream environments. Thus, the distribution of freshwater fish species and associated life history strategies across the insular freshwater ecosystems of the Indo-Pacific can be seen as a response to landscape. In particular, amphidromous and catadromous life histories can best be understood as benthic-pelagic larval migrations writ large across the landscape, with non-migratory low fecundity species possessing larval traits that facilitate survival in harsh, often unproductive, riverine habitats. In this presentation, I review and discuss evidence for this larval-centric view of freshwater fish life history across the Indo-Pacific, with a focus on recent work on New Zealand systems.
Major Trends in Fisheries: where they lead to and how we turn them around
Fisheries, in the past, were often not sustainable in the sense that people took deliberately less than they could, so they would have fish later. Although such sustainability existed – notably in the Pacific – overall, fisheries were protected only by the immensity of the oceans, and the depth and the dangers of navigation. This changed with the injection of fossil energy into fisheries systems, which started around the United Kingdom, the country that initiated the industrial revolution. Thus, since the late 19th century fisheries development has been an incessant expansion of industrial fishing, and the use, to exploit marine living resources, on an ever larger scale, of technologies developed for anti-submarine and other warfare.
For all practical purposes, and excepting a few hundred ‘stocks’ that are reasonably managed in countries such as the US, Norway or Australia, this has resulted in a massive reduction of the biomass of larger fish in all oceans. A result of that reduction is that industrial fleets, the world over, cannot operate without massive subsidies, one of the key reasons why, inexorably, East Asian, especially Chinese industrial fleets are replacing European fleets along the coast of developing countries whose own, usually smaller -scale fisheries, are under tremendous strain, notably due to population growth.
With global catches declining in spite – or rather because of – a globally increased effort, continued geographic and bathymetric expansion, is not a reasonable policy, even if fossil fuel continues to be cheap, government subsidies continue to be available, and the world continues to condone the use of semi-enslaved fishers on distant-water fishing vessels – all unlikely prospects. Rather, a reasonable policy would be for all maritime countries to rebuild their domestic fish populations using low quotas and area closures, then to exploit them sustainably. This, contrary to what too many people believe, could increase yields, and especially the profitability of fisheries.
This is also what would result from a closure of the high seas to all forms of fishing. This would not only increase the catch of tuna (because their population could rebuild in unfished areas), which would be caught only when they wander into the exclusive Economic Zone of maritime countries. This new distribution of catch would increase equity, as it would allow more countries to benefit from a resource now exploited primarily be few countries with distant-water fleets.
BLEEKER AWARD (Ecology) / Why fishes matter
Pieter Bleeker was one of the early pioneers of fish research. His primary goal was to identify the fishes that were present on the reefs of Indonesia. He worked in an era before the term ecology arose; what these fishes were doing was a question for the future. Today, what fishes do is critical. It is now widely accepted that it is the ecology of fishes, and more specifically their functional roles, that are important for the survival of aquatic ecosystems. In this talk I will explore the roles of fishes and how they have shaped our understanding of the world. Like Bleeker, my focus will be on coral reefs, for it is in these ecosystems that fishes have had perhaps the greatest impact. Fishes have shaped reefs for over 300 million years although the extent of their influence has increased markedly over time; from nibbling attached prey on early reefs to modern reefs where they dominate trophic interactions, determine benthic community composition, and even the structure and form of the reef itself. Today fishes influence almost every major ecological process on coral reefs from nutrient transfer to bioerosion. They are also the primary resource harvested by humans. They therefore have been the focus of much attention, being both fascinating and important. However, I believe their greatest contribution will be the role they play in shaping our future. For most of the last century, the functional operations of reef systems have been heavily influenced by fishing activity. As a consequence, we have responded with management approaches that protect biodiversity or exploited stocks (MPAs). However, our ability to identify, protect, maintain or restore critical ecosystem functions is still in its infancy. This inability has exposed our limitations. The global loss of corals has resulted in coral reef ecosystems that are fundamentally different to anything we have encountered before. It is in this future world that fishes will again lead the way. We have to recognize that coral reefs of the future are again going to be shaped by fishes and if we are going to steer reefs through the Anthropocene fishes are going to be our most important guides.
BLEEKER AWARD (Systematic) / The Kuroshio Current, an invisible barrier to shallow-water fishes of southern Japan
The Kuroshio Current flows in the West Pacific from the eastern side of the Philippines into the East China Sea between Taiwan and the southern tip of the Ryukyu Islands. It continues northward in the East China Sea along the Ryukyu Islands before returning to the West Pacific through the Tokara Strait in the northern part of the Ryukyu Islands. The Kuroshio Current washes the Pacific coasts of the main islands of Japan and turns eastward around the central part of Honshu Island eventually reaching the Hawaiian Islands. The Kuroshio is a very strong current flowing at a rate of about 3 knots and conveying 30 to 50 million tons of seawater per second. This strong, warm current transports many marine organisms including larval, juvenile and adult fishes from south to north and strongly influences the fish fauna of southern Japan.
In 2008 I organized a team of Japanese ichthyologists to study the fish fauna of southern Japan. The team intensively sampled shallow-water fishes in 12 locations along the Pacific coast of Honshu, Shikoku and Kyushu islands, and the Ogasawara and Ryukyu Islands. In addition to field surveys, the compositions of fish species at the 12 locations were analyzed using data in a huge Fish Image Database comprising 100,000 photographs of fishes. The faunal analyses of the 12 locations clearly revealed two assemblages of fish fauna in Japan: one inhabiting the main islands and the Ogasawara Islands located 1000 km south of Tokyo, and the other distributed in the Ryukyu Islands. The results strongly suggest that the Kuroshio Current plays an important role not only in transporting coral-reef fishes from south to north but also forms an invisible barrier for temperate fishes when they move south toward the Ryukyu Islands. The long-term surveys of fishes in the Kuroshio Current have also resulted in the discovery of many new species including a new pufferfish that constructs an amazing and elaborate circular spawning site on the sea floor.