Amino Acid and Fatty Acid Composition of Cultured Beluga (Huso huso) of Different Ages

The amino acids (AA) and fatty acids (FA) of Beluga (Huso huso) flesh at different ages were investigated as a source of AA and FA for human consumption. The analysis of Huso huso lipids (chloroform extracted) showed significant differences (p < .05) for specific FA with age. At all ages, the major saturated FA in Huso huso fillets was palmitic acid and the major unsaturated FA were oleic and docosahexanoic acid (DHA). Protein analysis indicated that the Huso huso muscle is well balanced with good levels of essential AA and appears to be a source of high quality protein (tryptophan was not measured) with methionine/cysteine as the first limiting AA. The major AA were glutamic acid, aspartic acid, and lysine. The results obtained from the present study show that Huso huso is an excellent protein and fat source when compared with other sturgeons.     

Diving behaviour of a Baird's beaked whale, Berardius bairdii, in the slope water region of the western North Pacific: first dive records using a data logger

A depth and temperature data logger was deployed by air gun on an individual Baird’s beaked whale (Berardius bairdii) off the Pacific coast of Japan. The retrieved data logger recorded 81 dives over approximately 29 h. The maximum recorded depth and the longest dive duration were 1777 m and 64.4 min, respectively. All dives were classified into three categories by depth: deep dives (>1000 m), intermediate dives (100–1000 m), and shallow dives (<100 m). Several intermediate dives generally followed a deep dive, and sequential shallow dives followed several intermediate dives in the record of the Baird’s beaked whale.     

Environmental factors and megafauna spatio‐temporal co‐occurrence with purse‐seine fisheries

Tropical tuna purse‐seine fisheries spatially co‐occur with various megafauna species, such as whale sharks, dolphins and baleen whales in all oceans of the world. Here, we analyzed a 10‐year (2002–2011) dataset from logbooks of European tropical tuna purse‐seine vessels operating in the tropical Eastern Atlantic and Western Indian Oceans, with the aim of identifying the principle environmental variables under which such co‐occurrence appear. We applied a Delta‐model approach using Generalized Additive Models (GAM) and Boosted Regression Trees (BRT) models, accounting for spatial autocorrelation using a contiguity matrix based on a residuals autocovariate (RAC) approach. The variables that contributed most in the models were chlorophyll‐a concentration in the Atlantic Ocean, as well as depth and monsoon in the Indian Ocean. High co‐occurrence between whale sharks, baleen whales and tuna purse‐seine fisheries were mostly observed in productive areas during particular seasons. In light of the lack of a full coverage scientific observer on board program, the large, long‐term dataset obtained from logbooks of tuna purse‐seine vessels is highly important for identifying seasonal and spatial co‐occurrence between the distribution of fisheries and megafauna, and the underlying environmental variables. This study can help to design conservation management measures for megafauna species within the framework of spatial fishery management strategies.     

Relative importance of chinook salmon abundance on resident killer whale population growth and viability

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First evidence of bubble-net feeding and the formation of ‘super-groups’ by the east Australian population of humpback whales during their southward migration

1. The recovery of overexploited populations is likely to reveal behaviours that may have been present prior to harvest but are only now reappearing as the population size increases. The east Australian humpback whale (Megaptera novaeangliae) population (group V, stock E1) has recovered well from past exploitation and is now estimated to be close to the pre-whaling population size.
2. Humpback whales were thought to follow a ‘feast and famine’ model historically, feeding intensively in high-latitude feeding grounds and then fasting while migrating and in calving grounds; however, there is growing evidence that animals may feed outside of known foraging grounds.
3. This short article reports on the first photographically documented evidence of bubble-net feeding by humpback whales in Australian coastal waters (n = 10 groups observed) and provides the first evidence of a second site in the southern hemisphere for the formation of ‘super-groups’ (n = 6 super-groups at discrete locations).
4. The formation of super-groups may be linked to changes in the type or density of prey available, either along the migratory route or in the feeding grounds of the previous summer. It is also possible that the increased population size following recovery make large group sizes while feeding more common. These findings strongly support evidence that feeding behaviour is not restricted to high-latitude foraging grounds in the Southern Ocean, and that prey consumption prior to leaving the coastal waters of Australia may be a significant component of the migratory ecology of this population.
5. Understanding how environmental variation influences the extent to which humpback whales depend on foraging opportunities along their migratory route, and where feeding occurs, will help to predict how future changes in the ocean will influence whale populations. This will also allow for more effective management measures to reduce the impact of threats during this important period of energy consumption.

     

Ecosystem modelling to quantify the impact of historical whaling on Southern Hemisphere baleen whales

Many baleen whales were commercially harvested during the 20th century almost to extinction. Reliable assessments of how this mass depletion impacted whale populations, and projections of their recovery, are crucial but there are uncertainties regarding the status of Southern Hemisphere whale populations. We developed a Southern Hemisphere spatial “Model of Intermediate Complexity for Ecosystem Assessments” (MICE) for phytoplankton, krill (Euphausia superba) and five baleen whale species, to estimate whale population trajectories from 1890 to present. To forward project to 2100, we couple the predator–prey model to a global climate model. We used the most up to date catch records, fitted to survey data and accounted for key uncertainties. We predict Antarctic blue (Balaenoptera musculus intermedia), fin (Balaenoptera physalus) and southern right (Eubalaena australis) whales will be at less than half their pre‐exploitation numbers (K) even given 100 years of future protection from whaling, because of slow growth rates. Some species have benefited greatly from cessation of harvesting, particularly humpbacks (Megaptera novaeangliae), currently at 32% of K, with full recovery predicted by 2050. We highlight spatial differences in the recovery of whale species between oceanic areas, with current estimates of Atlantic/Indian area blue (1,890, <1% of K) and fin (16,950, <4% of K) whales suggesting slower recovery from harvesting, whilst Pacific southern right numbers are <7% of K (2,680). Antarctic minke (Balaenoptera bonaerensis) population trajectories track future expected increases in primary productivity. Population estimates and plausible future predicted trajectories for Southern Hemisphere baleen whales are key requirements for management and conservation.     

基于改进FasterNet的轻量化小麦生育期识别模型

针对现阶段小麦生育期信息获取需依靠人工观测,效率低、主观性强等问题,本文构建包含冬小麦越冬期、返青期、拔节期和抽穗期4个生育期共计4599幅小麦图像数据集,并提出一种基于FasterNet的轻量化网络模型FSST(Fast shuffle swin transformer),开展4个关键生育期的智能识别。在FasterNet部分卷积的基础上引入Channel Shuffle机制,以提升模型计算速度。引入Swin Transformer模块来实现特征融合和自注意力机制,用来提升小麦关键生育期识别准确率。调整整个模型结构,进一步降低网络复杂度,并在训练中引入Lion优化器,加快网络模型收敛速度。在自建的数据集上进行模型验证,结果表明,FSST模型参数量仅为1.22×107,平均识别准确率、F1值和浮点运算量分别为97.22%、78.54%和3.9×108,与FasterNet、GhostNet、ShuffleNetV2和MobileNetV3 4种模型相比,FSST模型识别精度更高,运算速度更快,并且识别时间分别减少84.04%、73.74%、72.22%和77.01%。提出的FSST模型能够较好地进行小麦关键生育期识别,并且具有识别快速精准和轻量化的特点,可以为大田作物生长实时监测提供信息技术支持。     

A Norwegian Penthrite Granade for Minke Whales: Hunting Trials with Prototypes and Results from the Hunt in 1984,1985 and 1986

A penthrite grenade to replace cold harpoons in the Norwegian minke whale hunt was developed in 1983–1985. Data on survival times for 259 minke whales were collected from the trials in the 1984–86 hunting seasons, when 3 different prototypes were used. About 45% of the whales were killed instantaneously. The median survival time was 72 s. A substantially higher percentage of instantaneous deaths was recorded for penthrite grenades than for cold harpoons. The criteria for death were cessation of flipper movement, relaxation of the mandible, or sinking without any active movement. Some animals dived before the criteria could be controlled. If the central nervous system, heart, lungs or main vessels were damaged, a high percentage of the animals died instantaneously. In most cases, hits and detonations outside the thorax and central nervous system resulted in longer survival times than hits in the thorax. Survival time increased with whale size and range for animals not killed instantaneously. Marksmanship, technical and functional reliability of equipment and hunting techniques were all crucial to a good result. Better training of gunners, improved weapons and hunting equipment and more rapid reshooting of wounded animals would reduce the proportion of long survival times.     

基于IWHO-EKF的高速免耕播种机播种深度监测系统研究

为解决免耕播种机高速(12～16 km/h)作业时因地势起伏造成机械振动与传感器测量误差导致的播种深度监测系统精度降低,以及单一传感器监测可靠性较差的问题,研究了一种基于改进野马算法(Improved wild horse optimizer, IWHO)优化扩展卡尔曼滤波器(Extended Kalman filter, EKF)中关键参数Q_sigma、R_sigma1、R_sigma2、R_sigma3的多传感器数据融合算法(IWHO-EKF)的高速免耕播种机播种深度监测系统。首先,建立以激光、超声波与角度传感器为多传感器监测单元的播种深度监测模型;其次,通过卡尔曼滤波算法对3个单一传感器分别滤波;最后,提出一种加入莱维飞行与高斯变异的IWHO-EKF算法,将滤波后的3个单一传感器进行数据融合,从而解决机械振动干扰与传感器测量误差降低的问题,同时充分发挥多传感器融合信息,确保免耕播种机高速作业时实现高精度、高可靠性播种深度实时监测。为验证其优越性,通过IWHO-EKF算法与单一传感器监测、单一传感器滤...     

The Mammals Of Eastern Ethiopia

Seventeen confirmed and four probable sightings of humpback whales, Megaptera novaeangliae, were documented from platform-of-opportunity Research Vessel (R/V) Dr. Fridtjof Nansen in a passing-mode visual survey of continental shelf waters between Conakry and Cap Vert Peninsula (Dakar), 21 October -5 November 2011. None were encountered in the northern stratum Dakar-Agadir, 6 November -15 December 2011. Total visual survey effort was 468 h, 01 min, covering 5335 km. Depending on the exclusion or inclusion of probable records, the sum of group sizes totalled 33 or 43 individuals, respectively. Humpback whale encounter rates between Conakry and Dakar then amounted to 1.74 or 2.27 whales/ 100 km, respectively. Group sizes ranged from 1-6 individuals (mean = 1.94, S.D. = 1.20, n =17; median = 2). Minimally five of 17 groups (29.4%) consisted of adult-calf pairs, with a minimum crude birth rate ranging from 0.060-0.152. All sightings occurred in shallow water, 22-60 m (mean = 35.0 m, S.D. = 10.13, n = 17) but survey effort in deeper, off-shore water was negligible. Sea-surface temperature at sighting locations ranged from 25.5-29.0°C (mean = 27.34, S.D. = 0.96, n = 17). No humpback whales were sighted during a second survey covering Conakry-Tangier-Las Palmas, from 9 May to 22 July 2012 (519 h, 13 min; 6278 km). The Cape Verde Islands comprised, to date, the only known wintering ground located in the North-East Atlantic. This study showed that Senegal, The Gambia, Guinea-Bissau and Guinea are normal range states for M. novaeangliae. A temporal signature, six to seven months out-of-phase with mid-season in the Cape Verde Islands, and neonate presence strongly suggest that the wide Conakry-Dakar continental shelf serves as both wintering and nursery grounds for a South Atlantic stock, in agreement with Bamy et al. (2010). This stock may comprise the northwesternmost component of the large humpback whale assemblage migrating in and out of the northern Gulf of Guinea in austral winter/spring. Further research is required to consolidate insights linking temporal and spatial distribution off western Africa with hemispheric stock identity and migration paths.