Indonesia is a biodiversity hotspot threatened with new introductions of marine species. As with many countries, Indonesia has a stratified shipping network of international ports linked to a large suite of domestic ports. We developed a hub and spoke network model to examine the risk associated with the secondary transfer of introduced marine species from the port hub of Tanjung Priok in Jakarta Bay to the 33 Indonesian provinces (including other ports in the Jakarta province). An 11-year shipping dataset was used (vessel next port of call records for maritime vessels that originated in Jakarta Bay and that remained in domestic waters) to derive a province ranking of vulnerability. Fifteen provinces represented almost 94% of the traffic frequency, with East Java and Jakarta provinces dominating. All urban provinces featured within the top seven highest frequency traffic provinces. Traffic patterns reflect an intra-coastal reliance on shipping, with traffic frequency decreasing with distance from Jakarta Bay. Provinces were regionalized into three categories (Lampung to East Java, Makassar Straits, and Malacca Straits) each with different vulnerabilities based on their values.

We evaluated two risk models (bioregion pathway and species-based exposure), with the aim to determine an effective strategy to implement marine biosecurity risk management in regions/countries where biological data are limited. We used the Port of Tanjung Priok, Jakarta Bay, Indonesia, as a case study to test both models. The bioregion pathway model illustrates that Tanjung Priok is highly connected to the East Asian Sea (∼91%), and the Northwest Pacific, Mediterranean, and Australia & New Zealand bioregions (“Very Low” risk), with other bioregions posing “Negligible” risk, highlighting the importance of understanding regional port linkages. The bioregion pathway model strength is grounded by using readily available shipping data; however, it does not classify species into threat categories but considers a larger number of species as an increasing threat. The species exposure model found that 51 species pose a theoretical risk (10 “Moderate”, 20 “High”, and 21 “Extreme” risks) to Tanjung Priok. These 51 species can be used as a “watch list” for this port. If biosecurity measures for this port were restricted to the outcomes of the bioregion pathway model only 4 of the 51 species highlighted by the species exposure model would have been captured. The species model was data intensive, requiring extensive species datasets and consequently may be unsuitable when data are limited.

Highlight Research There are 26 species identified to be originated from the bay, which the highest diversity in Indonesia Six species found in Kwandang Bay is showing trends of decreasing populations and two species vulnerable based on IUCN conservation list Growth model and Fulton condition factor determined for 14 species indicates that they live in a good state of well beings in the bay The models and condition factors also reflect the adequate food resources required for grouper growth which makes Kwandang Bay as a good habitat for groupers   Abstract Grouper fishery has been the source of income for 3,700 fishermen in Kwandang Bay. Since 2017, grouper populations in Kwandang have been depleting due to the absence of management. This research aimed to analyze species composition, length-weight relationship, and condition factor of the groupers. Samples were collected from fishers who caught the fish using traps, speargun, and handline. Samples were identified through a method by Heemstra and Randall, while the length-weight relationship was estimated using log-linear regression and t-test. The number of specimens identified during January - December 2021 was 1,571 individuals. Research showed that those samples consisted of 26 species under eight genera. Six species found in Kwandang Bay were showing trends of decreasing populations and two species were vulnerable based on the IUCN conservation list. Length-weight relationship analysis of 14 grouper species resulted in b value ranging from 1.6359 to 3.4417 and R2 ranges from 0.7718 to 0.9858. A significant test at a 95% confident interval showed that 14 species had an isometric growth pattern. Fulton condition factors show that Kwandang Bay is an essential habitat for groupers, and the bay can support the fish growth due to the adequate food availability.

Abstract. Azmi F, Mawardi AL, Sinaga S, Nurdin MS, Febri SP, Haser TF. 2021. Population dynamics of Anadara antiquata of East Coast of Aceh, Indonesia. Biodiversitas 23: 436-442. Small-scale fishery effects are often overlooked by fishery and environmental managers. This study aimed to assess the impact of traditional cockle fishery on its population in the northeastern coast of Sumatra, Indonesia. The study took place from January 2018 to December 2018. Samples were obtained from Ujung Perling in Aceh Timur Regency, which is the only fishing ground exploited at present. Parameters estimated in this study include growth, mortalities, and exploitation levels. Analysis revealed that the average length was 50.03 mm, with the maximum shell length captured is 78 mm. Von Bertalanffy K-coefficient is 2.3 with a lifespan that can reach 3 years. Natural mortality is 2.27 year-1, while fishing mortality is 6.74 year-1. The exploitation rate in this study is 0.75. Growth parameters indicate that Ujung Perling is a suitable habitat for the cockle to grow, but mortalities and exploitation parameters suggest overexploitation is taking place in the area. To keep the population at a safe level, exploitation needs to be lessened to 33% from the current level.

The grey-eel catfish is a highly valued fish species in some parts of Indonesia. The fish is common in brackish water of estuaries, marine and freshwater habitat. They are not are not usually catched in commercial scale because of the limited population in its habitat. Although the status is not evaluated, the fish is predicted facing extinction in several countries. We conducted a study to examine the biological information and reproductive biology of the fish in Kota Langsa to gather information that can be utilize to evaluate reproductive status of the fish in several habitats. Parameters tested in the study includes sex ratio, length-weight relationships, candition factor, size at first maturity fecundity and reproductive potential of the fish. Research results provide information that the fish follows negative allometric model with constant condition factor throughout the study. The catches were relatively young fish which have not reached maturity stage. Fishes in the class sized at 510-550 mm provide the largest contribution to total eggs production. To ensure sustainability of the fish it is advised that the fish must catched at size larger than 550 mm.