Program

The United States and Japan have evolved different approaches to managing freshwater fisheries. In the United States, management is mainly at the state level by fisheries biologists. In Japan, management is at a local level by fishery unions and involves relatively few fishery biologists. Management in the United States reflects a public property rights philosophy that allows decision-making to be done at larger spatial scales. Operating at larger spatial scales provides for larger financial resources and fosters a landscape-level perspective because local management decisions can have repercussions for adjacent waterways. In Japan, management by fishery unions reflects a common property rights philosophy that allows decision making by small groups of individuals operating at smaller spatial scales but without the funding to hire fisheries biologists or collect extensive data. It is also difficult for unions to undertake expensive habitat improvement projects whereas such projects are a major activity of state management agencies in the United States. Management by fishery unions does have advantages. Because they operate at smaller spatial scales, fishery unions can exert better control over angling effort and respond more quickly to changes in fish populations. Members of fishery unions are likely to develop traditional ecological knowledge about their waterbody and have an emotional attachment to the fishery. Such an attachment produces a close-knit angling community where peer pressure reduces fishing violations and promotes a caretaker attitude toward the environment. The United States and Japan also differ in the prevalence of catch-and-release angling, types of harvest regulations, and use of fish stocking. Despite differences in management regimes, the United States and Japan face similar challenges in recruiting new anglers in the face of the declining interest in nature activities in today’s youth; dealing with anti-fishing sentiment; and meeting the conflicting mandates to provide sport-fishing opportunities while conserving native species.

In the developing countries and tropical areas, sometimes catch statistics is not collected by species but by gears. Feedback fishery management procedure (FFMP) is applied for determining annual allowable biological catch, and is successfully applied to the stocks that stock biomass estimation is not available for a single species. The application of FFMP would be a first step to introduce scientific management to developing country. The validation of FFMP to mixed species data was examined by using simulation. For simulating population dynamics of multispecies populations, Lotka-Volterra models were used, and virtual fishing operation were incorporated to the population dynamics assuming selectivity to each species under an assumed fishing effort. From the mixed species data obtained from the virtual operation, catch quota was calculated by using FFMP, and virtual operation is conducted following the calculated quota. For evaluating the population dynamics of each species, the efficiency of the stock usage and risk for the extinction are evaluated. From the preliminary result, FFMP will lead efficient and safe fishery management for the most of the cases, but low growing species has some risk to population collapse. In the presentation, recommendations for better application to real multi species fishery will also be discussed.

This study was conducted to further information that could be used as basis for management of fisheries in Malampaya Sound with reference to protection of Irrawaddy dolphins. Therefore, the aim of this study were to: gather information fishing gears catch in Malampaya Sound; 2. know the current fishing efforts of gears; 3. Determine the CPUE of major fishing gears and; 4. infer on interaction between fishing gears and Irrawaddy dolphins. The survey was conducted along six coastal barangays in the Sound through focused group discussions and onboard enumeration between 2016 and 2017.
The fishing gears with high fishing efforts in decreasing order were: shrimp gillnet, crab gillnet, fish bottom gillnet, and crab pots. Based on gear distribution, fishing efforts, and dolphin sightings, these gears have higher probability to be encountered by Irrawaddy dolphins.
Shrimp gillnet remained as most threat to Irrawaddy dolphins. Other gears which threaten the dolphins were: crab pots, crab gill net, fish bottom and surface gillnets, and must be regulated. Lift net which has a record in dolphin’s death in the past was already prohibited in the sound.
Push net, bottom gillnet, and panimbog (gillnet) were most efficient in terms of volume of catch/fisher/time, hence could be promoted in the sound, though push net operation should be regulated. There were regulations made in decreasing the types of fishing gears that affected dolphins in the Sound. However, additional policies should be in placed in order to ensure sustainable fisheries and more protection for dolphins.
In addition, pollutants, diseases, together with limited genetic diversity have all been also identified as threats to Irrawaddy populations. Thus, the bottom line for Irrawaddy conservation is to keep the population viable.

This paper is an initial study to highlight the effect of enforced regulation of Minister of Maritime Affairs and Fisheries of the Republic of Indonesia No. 2 / 2015 against fishing gears which are not environmentally friendly as well as the problem of climate change that affect small-scale fishers to the supply of fish. Tegalsari as coastal fishing port is one of the central marketing of fish and had a great fish auction in Tegal, Central Java, Indonesia. The problem that arises there is marketing of the fish supply due to effect of prohibition destructive fishing gear and uncertain climate change. To enhance the role Tegalsari as coastal fishing port and marketing of fishery products, it is necessary to improve in order to function optimally. This can be done through the fish supply chain management to be efficient and effective. Results of Gap Analysis showed improvements to be made by Tegalsari coastal port consisted of ( 1 ) the need for the transport of cold chain system, ( 2 ) the need for implementation of information systems related to the availability of the supply of fishery products, both in terms of price or quality of the products, ( 3 ) the need for the collaborative program in terms of research related to technology in improving the quality of fish, ( 4 ) the provision of information systems related to market information of fishery products both in domestic and world scale.

Estuarine systems in the Mexican Pacific are an important region for small scale fisheries, putting these environments under increasing pressure. Estuarine ecosystems play an important role in the maintenance of biological productivity and diversity, being essential habitats for many species of fish that habit these environments during part or all of their lifecycles, and are junctions of freshwater input from rivers and saline water from the sea, which gives them heterogeneous structural features and exclusive physiochemical conditions, and as a consequence high levels of primary and secondary production are often recorded. The presence of tidal channels that connect the seaward edge of an estuary with the interior landward-side of the system, increase the habitat complexity. These zones, usually inhabited by mangroves, facilitate the migration of organisms, and are used by fish of different life stages as resident, nursery or transient habitats. Several publications state the importance of mangrove forests as a key habitat for sustainable fisheries, but environmental conditions in some mangrove areas are extremely difficult for the survival of organisms (i.e. due to oxygen depletion). Thus, it seems that the role of mangroves is more related to the support of fisheries in surrounding habitats such as tidal channels, intertidal sand banks, seasonal flood plains, coastal lagoons and adjacent marine areas than “in situ” mangroves. We proposes the hypothesis that mangroves combined with freshwater inputs, tidal channels and coastal lagoons with tidal influence and seasonal floodplains are required for a mangrove forest to be considered an adequate fish habitat, and therefore an important fishing region. Riverine, fringe and over wash mangrove forests are more beneficial to fisheries than basin and dwarf mangroves that play different ecological functions other than supporting fisheries. The management of these ecosystems implicates the maintenance of an adequate hydrological regime.

Malaysian fisheries management has become a model for developing countries in Asia, yet it is comparatively unknown outside Asian region. During coupled decades, purse seine noticed as one of the most effective fishing gear contributing more landings and played significant role in Malaysian fisheries along with its catches. A set of conservation and management measures have been formulated and applied since mid-1980s, however the characteristics of Southeast Asian fisheries (i.e. as a multi-species, multi-gear, many fishers, landing sites, and data-poor situation) seemed to complicate its implementations. This study gives an overview of the existing management system and highlights some of its challenges. The most prominent measures are technical measures (i.e. closed fishing area, fishing zones, conservation of marine habitat), input controls (i.e. control on fishing effort and fishing units, registration of fishers) and community based fisheries management. Some valuable progresses have been accomplished, but the limitations of these measures remain, since they do not directly constrain the fleets from targeting and diminishing a certain individual stock in the mixed fishery. Therefore, a set of integrated adaptive measures are considerably needed to deal with these situations.

The Scientific Committee of the International Whaling Commission (IWC/SC) completed, in 1992, its development of a generic ‘single-stock’ management procedure for commercial whaling on baleen whales, called the ‘Revised Management Procedure (RMP)’. A major component of the RMP is its ‘Catch Limit Algorithm (CLA)’, a model-based harvest control rule found to be robust to inevitable scientific uncertainty through comprehensive simulation testing. The process of development can be regarded as the primary pioneering work in what is now termed ‘Management Strategy Evaluation’, i.e. the use of simulation frameworks for comparing and evaluating alternative management procedures in wildlife resource management. Since 1992, the RMP has been updated several times in the light of the implementation experience. The CLA itself use only time series of catch and abundance estimates (and their associated precision), and therefore it tends to be misunderstood that the management of whales does not require data other than the catch and abundance. In this presentation, I will introduce the concept of RMP and then illustrate how age data is useful for management of cetacean species. For this purpose, firstly, an analysis using the Antarctic minke whales was conducted to see if future age data are necessary to obtain reasonable precision of estimates of recruitment and recruitment rates. Also, simulation trials like RMP’s Implementation Simulation were undertaken in order to evaluate the extent of improvement in RMP-related performance that might be obtained by incorporating age data of whales. The results showed a clear indication of the value of the age data in understanding the population dynamics of Antarctic minke whales and hence improving their management, together with improving abilities to potentially detect the impact of climate change on this species. The details will be given in the presentation.

Small pelagic fish exhibit dramatic and cyclic population dynamics in response to climate variability. A typical example is the out-of-phase population oscillations between anchovy and sardine (species alternations) in the Kuroshio, California, and Humboldt Current systems. Key questions are why one species flourishes and the other collapses under the same ocean regime and why the patterns of species alternations can be synchronous despite the reversed temperature regimes between the opposite sides of the Pacific. This talk reviews hypotheses of biological mechanisms of species alternations in response to climate variability and presents our perspectives from some interspecific and intersystem comparisons among the Kuroshio, California, and Humboldt Current systems. Different hypotheses focus on different factors (e.g. temperature and food availability) and processes (e.g. bottom-up and top-down controls). Our concept holds that differential responses of vital parameters such as growth and spawning to environmental factors constitute a key to understand the mechanisms of species alternations. The trophic dissimilarities and similarities between anchovy and sardine were reported from different ecosystems. The optimal temperatures for early growth and spawning were contrasting between anchovy and sardine. Further, the anchovy–sardine relationships in terms of temperature and salinity preference were reversed between the opposite sides of the Pacific. The energy allocation strategies for reproduction could also differ dramatically between the species and between the systems. Overall, the responses to environmental factors were species-specific rather than genus-specific. Interspecific/intersystem comparison in a uniform approach, and multidisciplinary approach in which field, laboratory, and model studies are tightly connected, will need to be promoted.

The present study used otolith analysis-based body size back-calculation to: (1) evaluate the hypothesis of growth-dependent survival in young Pacific bluefin tuna (PBF; Thunnus orientalis) from the north-western Pacific Ocean; (2) identify critical developmental stages for survival; and (3) compare interannual differences in early growth. To this end, we compared the daily growth trajectories of a large number of larvae (standard length (SL) <15 mm), juveniles (15 ≤ SL ≤ 150 mm), and young-of-year (YOY; SL >150 mm) collected between 2011 and 2015. Otolith radius and SL were highly correlated and yielded a single relationship applicable for the five year-classes. Body size back-calculation showed that only larvae with fast, steady growth successfully transitioned to the juvenile stage. The ontogenetic analysis of daily growth rates revealed interannual differences only in larvae, and not in the larval stage of juveniles and YOY.
Neither sudden decreases nor increases in growth rates were observed during the larval stage of any of the stages, suggesting that the observed variability in larval body size may be the result of individual differences in growth rates rather than of drastic, one-time events. Overall, the results of the present study indicate that growth-dependent survival of larvae may be the most critical for PBF recruitment.
Otolith-based body size back-calculation with young Pacific bluefin tuna (Thunnus orientalis) from the north-western Pacific was used to test the hypothesis of growth-dependent survival and to identify critical developmental stages for survival. The results suggest that only the larvae with fast, steady growth successfully become juveniles and, hence, that growth-dependent survival in the larval stage is critical for recruitment.

Survival in early life stages of fishes is considered to be the main cause of inter-annual variability in their recruitment. Growth of larvae and juveniles is one of the most important factors for their survival. Rearing techniques for Pacific bluefin tuna (PBT) larvae have been remarkably developed for the last decade and enable us to investigate the detailed eco-physiological traits of PBT larvae. Although hatchery-reared larval PBT shows the shift of feeding habit from zooplanktivory to piscivory, there are no reports about piscivory of wild PBT larvae in fields. The objective of the present study is to elucidate the importance of piscivory for growth and survival in early life stages of PBT by rearing experiments. Firstly, we examined the influence of piscivory on growth of hatchery-reared PBT larvae. Rearing experiments revealed that the tuna larvae after onset of piscivory showed significantly faster growth than the tuna in zooplanktovious stage, which were supported by very high activity of the protein synthesis. Secondly, relationship between prey utilization and growth variation in hatchery-reared PBT larvae were investigated by nitrogen stable isotope and otolith analyses since marked growth variations of PBT larvae were observed in mass culture tanks. Nitrogen stable isotope analysis revealed that the larger fish rapidly shifted their prey to fish larvae, but smaller fish depended more on rotifers as the main prey item. Otolith analysis revealed that small growth variations during the early larval stage of PBT could induce subsequent large growth variations in the late-larval and juvenile stages through changes in their feeding habit. Our findings suggest that the piscivory is the key factor for growth of larval PBT and the growth variations induced by piscivory have the potential to lead to the inter-annual variations in recruitment success via growth selective survival process.

The development of fisheries is considered from various aspects, one of them is biological aspect. The biological aspect has important role for fisheries development in the area. Biological aspect for this research is useful to know the gastric composition of yellowfin tuna which landed on Pasar Lama. A total of 30 samples of yellowfin tuna’s gastric were taken on September 2015 - January 2016 from a fisherman in the Pasar Lama for the measurement of the total-length, total-weight, length-weight correlation analysis, and analysis of the gastric with frequency of occurrence method, volume organism method and preponderance index. The result of total-length and total-weight correlation analysis showed that yellowfin tuna in Pasar Lama have a value of b = 4,227 which classified as allometric positive. The result from preponderance index calculation of squid is 81,77%. Based on the conclusion, squid is categorized as main food for yellowfin tuna in Pasar Lama Kaur and based on the obtained result of length-weight correlation analysis, it can be described that the growth of weight of yellowfin tuna is faster than the growth of its length. Fishing gear used is boya lines (pancing boya), with the stretching rod consists of material size 10L jerry cans filled with foam as well as the length of rope used ± 100 m. The type of fishing fleet which is used for fishing operation is a fiber boat with dimenstion size of 9 x 1,5 x 1 m.