Significant changes in pelagic fish stocks of Clupeonella spp. in the south Caspian Sea

The present study was carried out during 2006-2007 along the southern Caspian Sea. The species composition showed that the common kilka, Clupeonella cultriventris caspia, is dominant species with 89% and then anchovy, C. engrauliformis, has shown only 8.7% while it was already dominant species in the past decades. The overall results indicated that common kilka was replaced with anchovy kilka as previous dominant kilka species due to invasion of Mnemiopsis leidyi to the southern Caspian Sea. Anchovy suffered greatly from M. leidyi so that the total catch dropped from 95000 mt in 1999 to less than 20000 mt in 2007. In our survey, 1415 fish specimens were collected randomly, including 221 anchovy, 281 bigeye and 913 common kilka. The mean length of anchovy was 117.8 ± 0.27 mm, while it was about 93.0 mm during 1995 to 1998 before the invasion of M. leidyi. Analysis of age classes indicated the mean age of 4.5 ± 0.04 years for anchovy, 3.6 ± 0.03 for common kilka and 4.6 ± 0.08 for big eye C. grimmi. According to the age and the length structure of the specimens in this study, it could be concluded that in recent years, young fish population of anchovy has been decreased in comparison with the last decade. The results showed that some biological characteristics of kilka population were affected by M. leidyi. Recently fishing activities take place in shallow waters where schools of kilka are in suitable density for fishing. According to our results, ctenophore occupied the anchovy habitat where it was mainly more than 50 m depth. The fishing has moved to areas with depths less than 50 meters where it was the main reason to change in species composition

ClimateFish: A Collaborative Database to Track the Abundance of Selected Coastal Fish Species as Candidate Indicators of Climate Change in the Mediterranean Sea

Under the effects of global warming, many animals and plants are undergoing rapid distribution shifts. These changes can be particularly rapid in marine fishes, and many species have responded markedly to recent increases in sea temperature. ClimateFish is an open-access database, which collates abundance data for 7 Mediterranean indigenous and 8 non-indigenous fishes, proposed as candidate indicators of climate change. These species have been selected by a network of Mediterranean scientists based on their wide distribution, responsiveness to temperature conditions and easy identification. Data are periodically collected according to a standard visual census protocol in four different depth layers. At present, the database collates data on a total number of 101'771 observed individuals belonging to the 15 target species. Counts were realized along 3142 transects carried out in 7 Mediterranean countries between 2009 and 2021. This database, associated with climate data, offers new opportunities to investigate spatiotemporal effects of climate change and to test the effectiveness of each selected indicator. Data are available at https://doi.org/10.17882/86784.The Mediterranean ClimateFish initiative was initially conceived by the international basin wide monitoring program CIESM Tropical Signals (funded by the Albert II of Monaco Foundation) and subsequently supported by the Interreg Med Programme (Projects: MPA-ADAPT, grant number 1MED15_3.2_M2_337 and MPA Engage, grant number 5MED18_3.2_M23_007), 85% co funded by the European Regional Development Fund

Arowana Fish Ponds Monitoring System Using CDMA-Based Wireless Communication

Arowana fishes demand good water quality for their healthy growth. A reliable water quality management system is very much required in order to maintain the water quality of the fish pond at optimum level. Manually checking the water quality of each pond one by one is very time consuming and inefficient. This project is aimed to develop a wireless monitoring system for Arowana fish ponds water quality. The water temperature and pH values of each pond are measured using sensors. Each pond sensor is connected to the Arduino Nano with RF module acting as base station, while the main monitoring station of the system uses a BeagleBone Black with Sierra wireless module and RF module. After data encoding, the sensors data from all base stations are sent to main monitoring system via pre-assigned frequency channel in each station. The main monitoring station retrieves data from the frequency channel. After decoding, the data will be sent to the cloud via the LTE network. Data analysis will be done in cloud to determine how the water quality of each pond affects the Arowana fish. Result shows that the system functions properly when the distance of data transmission is shorter than 100m and the maximum percentage error of data from water parameter sensor is acceptabl

Age-Specific Estimates Indicate Potential Deleterious Capture Effects and Low Survival of Stocked Juvenile Colorado Pikeminnow (\u3ci\u3ePtychocheilus lucius\u3c/i\u3e)

Hatcheries and stocking programs have become necessary to repatriate or augment populations of imperiled fishes worldwide. Over nearly two decades, millions of endangered juvenile Colorado Pikeminnow Ptychocheilus lucius have been stocked into the San Juan River (Colorado, New Mexico, and Utah); however, recruitment of these individuals to adult life stages (age ≥6) remains low. Using a mark–recapture data set collected from annual riverwide electrofishing efforts between 2003 and 2016, we investigated apparent survival and capture probabilities of stocked Colorado Pikeminnow to identify age‐specific bottlenecks contributing to this lack of recruitment. With relatively high capture rates, which averaged between 0.34 and 0.39 for the first 2 years after an individual\u27s first encounter, our results indicated that survival was consistently less than 0.25 for young age‐groups (i.e., ages 1–3), and no appreciable increase in survival occurred until fish had been in the river for at least 3 years (i.e., age ≥4+). Although age and capture effects were confounded for most age‐groups, capture appeared to reduce apparent survival for age‐2 fish by approximately 50%. The confounding effects of age, a completely hatchery‐origin population, and extensive environmental alterations to the San Juan River make it difficult to disentangle factors associated with this overall reduced juvenile survival

Integrative study of the krill-independent marine ecosystem in the Indian sector of the Southern Ocean

Ecosystem studies in the Southern Ocean have been intensively conducted in the Atlantic sector, where Antarctic krill (Euphausia superba) is a key species owing to its large biomass and geographically broad range. However, recent studies have indicated that an alternative energy pathway, a krill-independent food web, dominates in years and regions with lower abundances of krill in the Scotia Sea (Atlantic sector) (Murphy et al. 2007). In the Indian sector of the Southern Ocean, the geographical distribution of krill is limited to along the continental slope, and krill biomass is lower than that in the Atlantic sector. Thus, the krill-independent food-web is expected to be more important in the Indian sector. However, marine ecosystem studies in this region are still under development, and most research has focused on epipelagic waters. Therefore, the mesoand bathypelagic ecosystem of the Southern Ocean remains an unknown realm. In recent years, Japanese marine scientists have achieved progress in various scientific fields within the Southern Ocean, although only a few integrative science programmes have been undertaken in Japan. The scientific programme presented here aims to achieve a comprehensive understanding of the ecosystem in the Indian sector by combining results from individual disciplines that focus on physical and chemical processes, primary production, zooplankton, fish, and top predators. To accomplish this goal, we propose to investigate the following research topics:1) Ecosystems under the sea ice and in the vicinity of the ice edge (including applications of acoustic techniques [see point 6 below]).2) Epi- to bathypelagic ecosystems (including applications of acoustic techniques).3) Early life history and survival strategies of larval myctophid fishes.4) Biology of juvenile and adult myctophid fishes (monitoring abundance, biomass, food habits, and body size frequency as well as reproductive biology under the sea ice and in the vicinity of the ice edge).5) Monitoring of the distribution, migration, food habits, and nutrition conditions of top predators (penguins, flying sea birds, and seals).6) Development and establishment of the most recent acoustic techniques (which can be applied to the above ecosystem studies).7) Interactions between marine physics (sea-ice dynamics) and biological processes.Synthetic analyses of these results will allow the evaluation and prediction of how imminent long-term changes in physical and sea-ice dynamics will affect ecosystems in the Indian sector of the Southern Ocean.第4回極域科学シンポジウム特別セッション：[S] 南極研究の将来展望―第Ⅸ期6か年計画策定に向けて11月14日（木） 国立極地研究所 ２階大会議

Composición y riqueza íctica en quebradas y ríos del piedemonte de la cuenca del río Cusiana, Orinoquia colombiana

In order to provide information on the composition and richness of fish in the Colombian Orinoco piedmont (Tauramena - Casanare), collections were made every two months (June 2012 - February 2013), and standardized (arts-length-time), for six streams and three rivers from de Cusiana River piedmont, Orinoco River Basin, Colombia. 88 species where registered, 33 found on streams and 78 on rivers, there all grouped into six orders, 24 families and 56 genera. Two orders: Characiformes (43 sp.) and Siluriformes (34 sp.) and two families: Characidae (27 sp.) and Loricariidae (15 sp.) had the highest species richness. The results obtained increase the number of species to from the Cusiana River drainage by 26 species, for a new total of 141 species; nine of these had been considered endemic to other sub-drainages. There was also a record of a new order and family (Synbranchiformes: Synbranchidae) and a new genus Ceratobranchia. Eight of the reported species of the reported species require further confirmation because they are new records. The importance of fish diversity and human intervention that the Cusiana River drainage is suffering makes this research a tool for the conservation of this aquatic ecosystems and its fish species.Con el objeto de proporcionar información sobre la composición y riqueza de los peces del piedemonte de la Orinoquia colombiana (Tauramena - Casanare), se realizaron colectas bimestralmente (junio 2012- febrero 2013) y estandarizadas (artes-longitud-tiempo), para seis quebradas y tres ríos del piedemonte de la cuenca del río Cusiana, cuenca del Orinoco, Colombia. Se registraron 88 especies, 33 en quebradas y 78 para los ríos, agrupadas en seis órdenes, 24 familias y 56 géneros. La mayor riqueza la presentaron los órdenes Characiformes (43 sp.) y Siluriformes (34 sp.) y las familias Characidae (27 sp.) y Loricariidae (15 sp.). Los resultados obtenidos incrementan el número de especies para la cuenca media del río Cusiana en 26, para un total de 141. Nueve de estas habían sido consideradas como endémicas para otras subcuencas, registrándose un nuevo orden y familia (Synbranchiformes: Synbranchidae) y un género Ceratobranchia. Ocho especies de las reportadas necesitan ser confirmadas pues se trata de nuevos reportes. La importancia de la diversidad íctica y la intervención antrópica que sufre la cuenca del río Cusiana, hacen de esta investigación una herramienta para la conservación de estos ecosistemas acuáticos y sus especies de peces