Kepadatan Stok, Komposisi Jenis, Struktur Ukuran dan Daerah Penangkapan Ikan di Teluk Jakarta

Jakarta Bay has a variety of biota as a fishery resource, the utilization of which is continuous intensively. this study aims to obtain the data and information on stock density, species composition, size structure and fishing ground. The research was conducted by means of exploration and observation in 2016. The results showed that the average stock density in Jakarta Bay was 11,400 kg/km2 and in the Seribu Islands 25,500 kg/km2. Stock density distribution based on vertical coastline is obtained; mouth part 13,925 kg/km2, middle 11,709 kg/km2 and the coast 8,326 kg/km2. Coastal horizontal distribution; West area 15,311 kg/km2, Central 9,256 kg/km2 and East 9,259 kg/km2. Based on area in the Seribu Islands 25,500 kg/km2, Jakarta Bay 11,320 kg/km2 and Tangerang 11,610 kg/km2. Stock composition includes; demersal fish 84.53%, Cephalopods 9.98%, Crustaceae 4.32% and others. The fishing area of gill nets is wider and more spread out than other fishing gear.

Fishing capacity of South Baikal in terms of tourism development and limitations on fishing industry

The article considers eco-economic aspects of using the fishing capacity of the basin of South Baikal in the framework of the development of tourism of the coastal territory within Slyudyansky Municipal District of Irkutsk Oblast and within the entire southern Baikal Region. The article proposes to more strongly focus on developing sport and recreational fishing in this most developed area of Lake Baikal. The eco-economic and legal analysis carried out by the authors allows them to conclude that the traditional regulation of the stock of omul in Baikal by determining the total allowable catches and quotas is not effective enough, since it has led to the prohibition of not only industrial but also limitation of sport and recreational fishing for omul. At the same time, there is no reliable data that recreational fishing along the southern coast of Baikal is the reason for the decrease in the total stocks of omul in Baikal. On the contrary, the South Baikal fishing area can become the basis for a more dynamic development of the tourism industry in the region, including such types of it as cognitive tourism, ecological tourism and sports and recreational one. Moreover, it is the South Baikal fishing area and the coastal territory of Slyudyansky Municipal District that can become a testing site for developing more optimal (considering the specifics of various areas of Lake Baikal) ecological approaches to the regulation, rational use and reproduction of the stock of omul in Baikal for the purposes of sport and recreational fishing at Lake Baikal, as well as development of an environmentally friendly tourism industry in the region. The authors propose to review the strategy of fishery development of the stocks of omul at Lake Baikal and remove restrictions on recreational fishing, accompanying this with organizational and legal measures that allow obtaining reliable statistical data on catches. Precisely in this most economically developed area of Lake Baikal it is advisable to practice the organizational and legal mechanisms for the environmentally friendly development of tourist and recreational activities based on the available water bioresources of the unique lake.

(Re)Assembling Marine Space: Lobster Fishing Areas under Conditions of Technological and Legal Change in Atlantic Canada

Federal lobster fishing area (LFA) boundaries are part of the infrastructure controlling the temporal and spatial scale of lobster fishing in Atlantic Canada. Changes in the materiality of fishing and accompanying challenges to normative orders affecting access rules have together destabilized the spatial boundaries of LFAs. Changes in lobster distribution, gear innovations to fish in deeper waters, legal maneuverings over licensing, and competition with aquaculture for marine space all challenge LFA boundaries, which changes the distribution of fishing industry benefits and disrupts long-standing local values. Federal managers of the fishery struggle to deal with new assemblages of technology and law and how they interact with marine space. Examining the technology/legal pluralism nexus and their relationship with administrative lines in the water exposes how both affect more-than-human-spatial assemblages.

Information support for chub mackerel Scomber japonicus fishery in the Pacific waters of the Russian Federation

Methods of machine learning were applied for forecasting of chub mackerel fishing grounds in the South Kuril fishery district. The problem of perspective fishing area definition was reduced for a binary classification task, i.e. the sets of environmental conditions corresponded with presence or absence of fishing operations were determined for each point within the district. The fishery statistics for 2016–2020 and the data on SST with delay of 4–7 days from the date of catch, spatial SST gradients calculated using Belkin algorithm, and day-to-day SST variations were processed using LightGBM machine learning algorithm. The model was trained on the data for 2016–2019 and verified on the data for 2020. The AUC (as an aggregate measure of performance across all possible classification thresholds) varied from 0.65 to 0.92. In the fishery season of 2020, AUC was 0.69, on average, growing to 0.75 in the period of the highest catches. Approximately 75 % of the annual catch of chub mackerel was caught at the predicted sites in 2020; this portion reached 84 % in the period of the highest catches.

Kemiskinan Nelayan Tradisional Bermula Dari Wilayah Penangkapan Ikan

This research is motivated by a contradictory reality about the life of traditional fishermen. Traditional fishermen have “sacred” zones for fishing activities which are protected by law due to their highest biodiversity and cultural importance to local fishing communities. On the other hand, 76 percent of the traditional fishermen are classified as poor; the level of poverty headcount index (PHI) reaches 32.4 percent. Based on this contradictory situation, 2 (two) important questions arise: what happens in the fishing area of traditional fishermen and whether the poverty experienced by traditional fishermen starst from this fishing ground. This research took place in Bagan Kuala, a village where the majority of the population are traditional fishermen. This study used an ethnographic approach with two data collection tools, which are interviews and observations. It was found that each traditional fisherman in this village has its own fishing grounds and boundaries. The boundary is marked by fish aggregating device (FAD), which also serve its purpose as fish catcher. Some of the FADs have been owned by fishermen for many generations. Outsiders often trespass this fishing ground, particularly at night where they use modern tools like trawl, destroying the fishermen’s FADs. As a result, there are conflicts and also negotiations involving the locals and outsiders who asked for their permission; the catch was divided depending on the agreement. From these findings, it can be concluded that poverty can start from the fishing ground.

Fine-scale behavior of red snapper (Lutjanus campechanus) around bait: approach distances, bait plume dynamics, and effective fishing area

The behavior of fish around bait is poorly understood despite it being important for the fish catching process and estimating relative abundance. We used a fine-scale acoustic positioning system to quantify the movements of 26 red snapper (Lutjanus campechanus) around 120 bait deployments in 2019 at a natural reef site (~37-m deep) in North Carolina, USA. There were 39 instances of tagged red snapper approaching bait during four baiting days, some of which approached due to apparent sensory cues (28%) while most approached incidentally (72%). Tagged red snapper approached bait from initial distances of 1 to 1 147 m (median = 27 m; mean = 86 m), and took 0 – 77 min (mean = 22 min) to approach. Fish were more likely to approach bait if they were located close to, and down-current of, the bait at deployment. Our estimated effective fishing area of 2 290 m2 (within which >50% of red snapper responded to bait) could be used along with video counts and other information to estimate densities of red snapper.

SEBARAN RUMPON PESISIR PADA DAERAH PENANGKAPAN PURSE SEINE DI PERAIRAN DESA URENG KECAMATAN LEIHITU, KABUPATEN MALUKU TENGAH

The Fish Aggregating Devices (FADs) have been utilized for a long time by the purse seine fishermen in Ureng. This research was aimed at mapping the devices operating by Ureng fishermen and indentifying the dominant captured fish surrounding the set devices. This research was conducted in Lihitu district, Central Maluku Regency. The results showed that there was one large circle that resembled a ball with several groups of five small circles inside. Based on the type, the dominant fish caught around the FADs were mackerel (45 ton), mackerel tuna (25 ton), and skipjack tuna (20 ton). Overall, this study found that the catch using the purse seine in the five FAD groups was dominated by small and medium sized fish. In conclusion, under the potential fishing area for purse saine fishermen in Ureng, if the distance between the FADs is adjusted, fish are not trapped forever in the FADs and can migrate, lay eggs in other areas outside the waters of Ureng.

Metagenomics Analysis Reveals an Extraordinary Inner Bacterial Diversity in Anisakids (Nematoda: Anisakidae) L3 Larvae

L3 larvae of anisakid nematodes are an important problem for the fisheries industry and pose a potential risk for human health by acting as infectious agents causing allergies and as potential vectors of pathogens and microrganisms. In spite of the close bacteria–nematode relationship very little is known of the anisakids microbiota. Fresh fish could be contaminated by bacteria vectored in the cuticle or in the intestine of anisakids when the L3 larvae migrate through the muscles. As a consequence, the bacterial inoculum will be spread, with potential effects on the quality of the fish, and possible clinical effects cannot be discarded. A total of 2,689,113 16S rRNA gene sequences from a total of 113 L3 individuals obtained from fish captured along the FAO 27 fishing area were studied. Bacteria were taxonomically characterized through 1803 representative operational taxonomic units (OTUs) sequences. Fourteen phyla, 31 classes, 52 orders, 129 families and 187 genera were unambiguously identified. We have found as part of microbiome an average of 123 OTUs per L3 individual. Diversity indices (Shannon and Simpson) indicate an extraordinary diversity of bacteria at an OTU level. There are clusters of anisakids individuals (samples) defined by the associated bacteria which, however, are not significantly related to fish hosts or anisakid taxa. This suggests that association or relationship among bacteria in anisakids, exists without the influence of fishes or nematodes. The lack of relationships with hosts of anisakids taxa has to be expressed by the association among bacterial OTUs or other taxonomical levels which range from OTUs to the phylum level. There are significant biological structural associations of microbiota in anisakid nematodes which manifest in clusters of bacteria ranging from phylum to genus level, which could also be an indicator of fish contamination or the geographic zone of fish capture. Actinobacteria, Aquificae, Firmicutes, and Proteobacteria are the phyla whose abundance value discriminate for defining such structures.

Development of biological resources of the Volga-Caspian fishing area in 1918-1930 (historical overview)

The state of biological resources of the Volga-Caspian fishing area in the period from 1918 to 1930, before the construction of a cascade of hydroelectric power stations, is considered. The «Big Volga» plan was supposed to solve transport, irrigation and energy problems, as the most important for the industrial development of the country, the harm to fishing was perceived as an inevitable loss. Drastic changes in the hydro regime of the river, deterioration of its water quality, dams that prevent fish from spawning, led to a further decrease in catches.