Occurrence of potential plastic microfibers in mussels and anchovies sold for human consumption: Preliminary results

There is a global concern over the impact of microplastics on marine species and trophic webs. Microfibers commonly represent the greater portion of microplastics in the aquatic environment, but little is known about fiber uptake and accumulation by marine biota. The aim of the study was to investigate the potential plastic microfiber contamination in mussels (Mytilus galloprovincialis) and anchovies (Engraulis encrasicolus) from the Tyrrhenian Sea sold for human consumption. Anthropogenic debris was extracted from the digestive tracts of fish and the whole shellfish using a 10% KOH solution and quantified under a light microscope. The preliminary results showed the occurrence of potential plastic and natural microfibers in 73% of the samples. On average mussels contained 1.33 microfibers/g w.w. and 7.66 items/individual, while anchovies contained 9.06 microfibers/individual. Considering that mussels are consumed as a whole, and small pelagic fish, as anchovy, may be eaten without removing the gastrointestinal tract, microfiber contamination may lead to human exposure. More research is required to adequately assess the risk that microplastics, including microfibers, may pose for food safety and human health.

Modeling small-pelagic fish biomass in the Indonesian seas: climate variability and climate change impacts

The present study uses the Community Earth System Model, version 1– Biogeochemistry [CESM1(BGC)] to examine the influence of climate variability and climate change on small pelagic fish biomass in the Indonesian seas. The fish biomass was calculated based on a fish production model according to primary production and energy transfer at the tropic level. The primary production data were obtained from results of CESM1(BGC) model from 1850 to 2015. Empirical orthogonal function (EOF) analysis of the calculated fish biomass identifies three regions in the Indonesian seas that are associated with coastal upwelling. These regions are located in (1) southern coast of Central Java Province until west-coast of West Sumatra Province, (2) southern coast of Central Java Province until the southern coast of Bali Province, and (3) Banda-Arafura Seas. Fish production variability in these regions exhibits semi-annual, annual, and IOD-ENSO related signals. Climate change impact for RCP 4.5 scenario produces ‘fish stock increase status’ in 2025 for the three regions, while the ‘fish stock current status’ will reoccur in 2050, except for the western part of Sumatra (part of region-1) which alters to ‘fish stock decrease status’.

Composition, Density and Spatial Distribution of Zooplankton in Inner Ambon Bay, Indonesia

Inner Ambon Bay is part of Ambon Bay; it is semi-closed area and a small pelagic fish fishing ground, especially anchovy. The anchovy is a zooplankton predator; therefore the existence of anchovy is affected by the abundance of zooplankton. The aims of the research are to obtain information on the composition, density, and spatial distribution of the zooplankton in these waters. Data of zooplankton composition were obtained from sampling by using plankton net at ten observation stations. Meanwhile, data of densities were collected using a scientific hydroacoustic system, BioSonic DTX supported with split-beam technology, on six parallel transect lines and one cross-parallel transect line. Geostatistical analyses technique was used to describe horizontal distributions of zooplankton, and vertical distributions pattern were plot in the graphs. The result shows that the zooplankton community is dominated by Copepod and meroplankton. The highest average density was found in August (9393 ind./m2),while the lowest density was in June (903 ind./m2).

Current (2021) status of surimi industry in Indonesia and possible solutions: A review

The surimi industry in Indonesia, especially located on the North Coast Java, has an important role in boosting both regional and national economy. In the last 5 years, the surimi industry has been affected by the policy of prohibiting the use of destructive seine and trawl nets, known locally as cantrang. Most of the surimi industry in Indonesia use bycatches and discards of cantrang as raw material. On the other hand, the policy drives the opportunity to use the aquaculture fishes and non cantrang catches as a raw materials substitution of the surimi. Many laboratory scale observations have shown that aquaculture and small pelagic fish can be used as the raw material for surimi. However, the information around using several species of fish (multi-species) as raw material of surimi is not well provided. Therefore, the purpose of this study was to generate the recommendations regarding the use of multi-species fish as an alternative raw material for the surimi industry to replace the bycatches of cantrang. The information will allow industry both small and medium size to have a better option that suits their need to be able to fulfill the market demand.

Characteristics of purse seine fisheries in the Sulawesi Sea (case study in Tumumpa fishing port)

The purse seine is the dominant fishing gear operating at the Tumumpa Fishing Port with a vessel of >90%. The purse seines that have developed are large pelagic targets, with the main catch targets being skipjack, mackerel tuna, and tuna. Tuna, mackerel tuna and skipjack are important commodities for fisheries in Indonesia. This study aims to determine the characteristics of purse seine fishing gear and its catch in the Sulawesi Sea. Data collection was carried out for two years from 2019-2020 at Tumumpa Fishery Port. Indications for the use of fish resources are calculated by comparing the length-at-first-capture (Lc) with the length-at-first-mature (Lm). The results showed that purse seines are very dominant in exploiting large pelagic resources (skipjack, mackerel tuna and tuna) with the proportion reaching 78%, small pelagic (21% scads and 1% other fish). The large pelagic fishing season using the purse seine vessel occurs in May – November, with 2 peak seasons in July and September. While the small pelagic occurs in May – September, with the peak occurring in July. The size when the frigate tuna was first caught was at a fork length of 25.15 cm (Lc) and Lm in a size of 28.52 cm for females and 28.29 cm for males. Meanwhile, the first scads was caught (Lc) at a length of 21.4 cm with the length-at-first-mature (Lm) being 20 cm for the female and 19 cm for the male. Based on this analysis, it was shown that the purse seines is a selective fishing gear for small pelagic fish but not selective for large pelagic fish.