One of the fishery resources that have high economic value are demersal fisheries resources in deep sea waters. The results ofthis study found 22 demersal fish species with high economic value captured by fishermen. The results ofthe study found as many as 22 species, five fish stretcher 5 that can be foundin nearly all areas and fishing season. Five types of fish are: lencam (Lethrinus sp.), kurisi (Etelis spp), kerapu (Ephinephelus sp), red snapper (Lutjanus spp), bubara fish (Caranx sp). The types of fish catches were found spread around the waters of Ambon Island. The potential at Maxsimum sustainable Yield (MSY) of fish grouper (Epinephelus spp) 572.02 with 15.75 tonnes optimum effort trip. The average production of 178.919 tonnes currently. Thus the average utilization rate of groupers currently 31.27% or 68.72% untapped. If it is based on the MSY allowable catch for the fish species is 457.60 tons / year. MSY red snapper (Lutjanus spp) 146.83 wih 2.631 tonnes optimum effort trip. Average production is currently 67.704 tons. Thus the average utilization rate of the red snapper fish is currently 47.47%, or in other words the potential for red snapper untapped 52.52%. If it is based on the MSY allowable catch for the fish species is 117 464 tons / year. MSY bubara fish (Caranx sp) 270.60 tonnes with optimum effort 3630 trip with an average yield of 72.96 tons.

Ambon Bay is one of the centers of economic activity held by the Ambon City community and is vicinity area. The fishing sector is one of the activities found in this area. The kind of fishing activity and its related problem faced by the fishermen of this area is the content of this study. This study was aimed to investigate the kind of fishing gear operated in this area and to identify problems faced by the fishermen in conducting their activity. Data were obtained from 91 fishermen fishing in this area with various types of fishing gear and conducted through interviews and field observation. Data obtained were then analyzed descriptively. Kind of fishing gears found to operate in Ambon Bay consists of gill net, hand line, beach seine, bottom longline, lift net, purse seine, and trap net. The common problem face by the fishermen is plenty of floating debris, high turbidity caused by flooding. All these problems hampering the fishing activity that leads to a decline in fish production and fishermen’s income. Another problem that occurs is the increase of fishing gear operated in the area with relatively a small fishing area apart from fish resources that already decrease compared to 15 – 20 years before. From field observation and interviews with the local fisher, it was found that fish production has declined up to 50%.

Changes in internal and external factors during operation of bottom gill net will affect to catch ability of bottom gill net. The presence of marine debris in the ocean is predicted to influence the internal factors of gill nets which leads to reduction of catch ability. This study aimed to identify the factors that lead to decreasing of catch ability of bottom gill nets and to calculate the reduction of catch ability due to changes in hanging ratio caused by marine debris. Fishing activity using bottom gill net for 10 replications was conducted to identify the factors that affect the bottom gill net’s catch ability, while the reduced catch ability is calculated through the percentage of net area covered by garbage, changes in the hanging ratio and tension of the net body due to the entangled and twisted garbage in the net. The results showed that there were three factors that led to a reduction in the catch ability of bottom gill nets due to marine debris, namely: garbage stuck to the body of the net, trash entangled in net webs and trash wrapped around the body of the net. The closure of the mesh, changes in openings of mesh and net tension result in a decrease in the catch ability of bottom gill nets by 20-50%.