Diel differences in blue whale (Balaenoptera musculus) dive behavior increase nighttime risk of ship strikes in northern Chilean Patagonia

The northern Chilean Patagonia region is a key feeding ground and a nursing habitat in the southern hemisphere for blue whales (Balaenoptera musculus). From 2014 to 2019, during 6 separate research cruises, the dive behavior of 28 individual blue whales was investigated using bio-logging tags (DTAGs), generating ≈190 h of data. Whales dove to significantly greater depths during the day compared to nighttime (day: 32.6 ± 18.7 m; night: 6.2 ± 2.7 m; P < 0.01). During the night, most time was spent close to the surface (86% ± 9.4%; P < 0.01) and at depths of less than 12 m. From 2016 to 2019, active acoustics (scientific echosounders) were used to record prey (euphausiids) density and distribution simultaneously with whale diving data. Tagged whales appeared to perform dives relative to the vertical migration of prey during the day. The association between diurnal prey migration and shallow nighttime dive behavior suggests that blue whales are at increased risk of ship collisions during periods of darkness since the estimated maximum ship draft of vessels operating in the region is also ≈12 m. In recent decades, northern Chilean Patagonia has seen a large increase in marine traffic due to a boom in salmon aquaculture and the passenger ship industry. Vessel strike risks for large whales are likely underestimated in this region. Results reported in this study may be valuable for policy and mitigation decisions regarding conservation of the endangered blue whale.     

我国小型潜水电泵行业发展与思考

论述了我国小型潜水电泵行业概况及主要生产基地浙江省温岭市小型潜水电泵现状，并对小型潜水电泵今后发展提出要扶强治劣、加强技术和信息交流、积极开拓国际市场、提高技术水平、推行名牌战略等建设性建议。     

枸杞岛海藻场大型底栖无脊椎动物摄食类群研究

随着海洋生态学研究的深入和海洋环境监测的需要,一些传统的研究方法如多样性指数等在评价大型底栖生物群落结构变化时显得说服力不足,而摄食功能群的研究越来越受到重视。本实验根据2012年8月对浙江枸杞岛海藻场大型底栖无脊椎动物的调查实验,分析该海域夏季大型底栖无脊椎动物摄食类群的组成、空间及数量分布,并进行相关生态评价。结果表明,枸杞岛海藻场夏季大型底栖无脊椎动物组成以肉食者和滤食者占较大优势,食碎屑者、植食者和食底泥者次之,杂食者最少;肉食者的优势种为布尔小笔螺、寄居蟹、扁平管帽螺、甲虫螺和四齿矶蟹等,滤食者的优势种为条纹隔贻贝、带偏顶蛤、短石蛏和布氏蚶等,植食者的优势种为钩虾、单一丽口螺和锈凹螺等;各摄食类群水平分布较均匀,垂直分布受水深和摄食饵料的限制;基于大型底栖无脊椎动物功能类群的生态参数评价结果表明,枸杞岛海藻场大型底栖无脊椎动物群落健康状态呈虚弱水平,大部分站位大型底栖无脊椎动物群落受到轻度扰动,底栖生态质量状况较好。     

Comparison of two methods of sub-sea sampling of the Guernsey ormer,Haliotis tuberculata L.

Abstract The ormer, Haliotis tuberculata L., is the only abalone species found on the coasts of western Europe, its northern most limit of distribution being the Channel Islands. Previous Guernsey ormer population studies were based upon a form of catch-per-unit-effort sampling where the unit of effort was one diver, searching the substrate for 5 min continuously. An ormer population survey was carried out in the waters around Guernsey, using this former method concurrent with an alternative system of sampling by area using 10 m² quadrats at randomly selected locations. The published results of a series of earlier surveys include a measure of ormer density m^-2 which, along with knowledge of the extent of suitable substrate, allows tentatively for absolute abundance to be estimated. This study demonstrates that an estimate obtained in this way may be unreliable. Statistical comparison of the population size structures derived from the two different sampling methods also showed considerable inconsistency. The implications of this for management of the Guernsey ormer stock are considered.     

Diving behavior of immature, feeding Pacific bluefin tuna (Thunnus thynnus orientalis) in relation to season and area: the East China Sea and the Kuroshio–Oyashio transition region

Twenty‐four archival tags were recovered from Pacific bluefin tuna previously released off Tsushima Island in the East China Sea. By analysis of the time‐series data of the pressure and the ambient and internal temperature from the 24 tags, we examined the relationship between the tuna's pattern of diving and the thermocline depth. In the East China Sea, diving and feeding events occurred throughout almost the entire day in both winter and summer, suggesting that the purpose of diving is for feeding. In summer, the feeding frequency was greater than that in winter, which corresponds to the fact that growth is more rapid in summer than in winter. During summer in the Kuroshio–Oyashio transition region, on the other hand, feeding events were much more frequent than those in the East China Sea, in spite of a lower diving frequency. The mean horizontal distance traveled was also significantly higher and it seems that in this area they may move horizontally to feed on prey accumulated at the surface. We conclude that, in addition to the ambient temperature structure, the vertical and horizontal distribution of prey species plays an important role in the feeding behavior of Pacific bluefin tuna. One bluefin tuna migrated to the Oyashio frontal area, where both the horizontal and the vertical thermal gradients are much steeper. The fish spent most of the time on the warmer side of the front and often traveled horizontally to the colder side during the day, perhaps to feed. This implies that there is a thermal barrier effect, in this case from the Oyashio front, on their behavior. The frequency of feeding events was low, although all the monitored fish dived every dawn and dusk, irrespective of the seasons or location. It is possible that these twice‐daily diving patterns occurred in response to the change in ambient light at sunrise and sunset.     

潜水电泵在坡地喷灌工程中的应用前景

本文在分析南方坡地灌溉工程特点的基础上，阐述了坡地喷灌工程选用潜水电泵的优势，并通过一个典型喷灌工程不同泵型及泵站设计方案的对比，探讨了潜水电 泵在坡地喷灌工程应用的可行性及其有待解决的技术问题。     

Attitudes,beliefs, and prevalence of dumpster diving as a means to obtain food by Midwestern,low-income,urban dwellers

Dumpster diving is a term generally used for obtaining items, in this case food for consumption, from dumpsters. This study evaluates the prevalence of dumpster diving in two low-income urban communities in Minneapolis, Minnesota. Additionally, attitudes and beliefs of adults who engage in this behavior are reported. Surveys (n=396) were used to collect data including individual dumpster diving behavior, food security, health, and demographic data. Nearly one-fifth of those surveyed had used dumpster diving as a means to obtain food. Focus groups (n=17) were conducted to further evaluate dumpster divers attitudes and beliefs about dumpster diving, use of food assistance programs including benefits and barriers, and other strategies used to obtain food such as stealing. Focus group participants were primarily homeless and most were high school educated. Ways to improve delivery of food assistance are suggested. In conclusion, more research on the use of dumpsters as a source of food is needed. Utilizing more of the 96 billion pounds of food wasted each year in the US through food recovery and donation programs could help to provide socially acceptable means for low-income urban dwellers to obtain food.     

Assessing cetacean body condition: Is total lipid content in blubber biopsies a useful monitoring tool?

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Stress and mortality in the supply chain of live scallops Pecten maximus L., from scuba diver to market

Here, we report results from a project where the aim was to study stress and mortality in the supply chain from harvest to market for live scallops Pecten maximus L., hand‐picked by scuba divers. With experiments conducted both during the warm (September) and cold (April) seasons, emphasis was put on how mechanical influence, stacking height, post‐harvest water storage and dry transport affected scallop fitness. When scallops were exposed to mild‐ or hard mechanical shocks (dropped three times from 50 or 150 cm), it was found that hard mechanical shock caused up to 90% mortality during subsequent water storage. Results from the experiments where scallops were stored at different stacking heights (15, 30 and 50 cm) in water showed that both the duration of storage and the stacking height had a significant effect on mortality. Higher stacking heights also affected survival in subsequent transport. For long‐term storage (>7 days), it is recommended to limit the stacking height of scallops stored in tanks to reduce risk of mortality. Respiration experiments showed an average oxygen consumption of 0.10 and 0.24 mg O₂ min^?1 kg^?1 f.w. in the cold and warm season respectively. Water supply during storage of scallops should be adjusted to water temperature and biomass. Registration of mortality and analysis of the Adenylic Energy Charge of scallops followed through the production cycle from harvest to market indicate that it is the sum of stressors that are determinable for final survival.     

Impacts of intensive recreational diving on reef corals at Eilat, northern Red Sea

Coral reefs at Eilat, northern Red Sea, are among the most heavily used in the world for recreational diving, with >250,000 dives per year on only 12 km of coastline. We assessed patterns of dive frequency, diver behavior, and coral damage on selected reefs at Eilat, in order to determine impacts of diving tourism. Frequencies and types of recreational SCUBA dives varied widely between 12 coral reef sites, with >30,000 dives per year at the most heavily-used sites. Field observations of diver behavior revealed ca 10 incidents of reef contact per dive, mostly via raising of sediments onto the reef, but also involving direct breakage of corals. The proportion of damaged coral colonies varied significantly with the frequency of SCUBA diving, and did not depend upon site topography. We conclude that current rates of recreational diving on some reefs at Eilat are unsustainable, resulting in damage to the majority of stony coral colonies. This study reveals consequences of diving tourism at extremely high levels of use. Our estimate of diver carrying capacity for reefs at Eilat is similar to levels proposed for other reef sites around the world.