Predation on fish by cormorants and pelicans in a cold-water river: a field and modeling study

1997 ◽  
Vol 54 (7) ◽  
pp. 1480-1493 ◽  
Author(s):  
C E Derby ◽  
J R Lovvorn
Keyword(s):  
Cold Water ◽  
Pimephales Promelas ◽  
Fresh Mass ◽  
Phalacrocorax Auritus ◽  
Bird Predation ◽  
Overwinter Survival ◽  
Platte River ◽  
Bioenergetics Model ◽  
The North ◽  
Pelecanus Erythrorhynchos

We studied diets of double-crested cormorants (Phalacrocorax auritus) and American white pelicans (Pelecanus erythrorhynchos) collected on the North Platte River, Wyoming, from May to August. Rainbow (Oncorhychus mykiss) and cutthroat (O. clarki) trout 10-16 cm long were stocked in late June - early July. Cormorants ate mainly suckers (Catastomus spp., 61% of numbers, 85% of fresh mass) before trout stocking; but trout consumed increased from 17% (12% of mass) in samples before stocking to 60% (82% of mass) after stocking. Pelicans ate mostly suckers (64% of numbers, 84% of mass) and minnows (Rhinichthys cataractae, Pimephales promelas; 21% of numbers, 1% of mass) throughout the study; trout were 1% (0.1% of mass) of the pelican diet before stocking, and 22% (14% of mass) after stocking. A bioenergetics model estimated that these birds consumed up to 80% of trout stocked in 1994. In August 1993, cormorants ate mostly trout (86% of numbers, 98% of mass), suggesting that many stocked trout survived until autumn. However, the much smaller fraction of trout eaten by cormorants in spring 1994 before stocking (mean 17% of numbers, 13% of mass) than after stocking (60% of numbers, 82% of mass) suggests that stocked trout declined substantially during winter. Because overwinter survival might have limited trout recruitment between years, it is unclear whether bird predation was additive or compensatory.

Greater predation by Double-crested Cormorants on cutthroat versus rainbow trout fingerlings stocked in a Wyoming river

1999 ◽  
Vol 77 (12) ◽  
pp. 1984-1990 ◽  
Author(s):  
James R Lovvorn ◽  
Daniel Yule ◽  
Clayton E Derby
Keyword(s):  
Rainbow Trout ◽  
Cutthroat Trout ◽  
Phalacrocorax Auritus ◽  
Limited Data ◽  
Platte River ◽  
The North ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Oncorhynchus Clarki Bouvieri ◽  
Pelecanus Erythrorhynchos ◽  
Yellowstone Cutthroat Trout

We studied the relative vulnerability of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) versus rainbow trout (Oncorhynchus mykiss) stocked as fingerlings in the North Platte River, Wyoming, to Double-crested Cormorant (Phalacrocorax auritus) predation. Cutthroat fingerlings decreased as a fraction of the population from stocking in late June to electrofishing surveys in the following October and March. In contrast, the fraction of cutthroat fingerlings among tagged fingerlings eaten by cormorants collected on the river was significantly greater than that in the population when originally stocked. More limited data from pellets regurgitated by adult cormorants at a nearby colony and in American White Pelicans (Pelecanus erythrorhynchos) collected on the river showed the same trend toward greater percentages of cutthroat trout being consumed than were present among trout stocked. There were no differences in cormorant predation rates on the Eagle Lake strain of rainbow trout reared under shaded versus partially shaded conditions, or between Auburn and Bar BC strains of Snake River (Yellowstone) cutthroat trout. On the North Platte River, cutthroat trout fingerlings were more susceptible to cormorant predation than rainbow trout of similar size that were stocked simultaneously.

Phytoplankton of cold-water lake ecosystems under the influence of natural and anthropogenic factors

2021 ◽  
pp. 42-49
Author(s):  
Andrey N. Sharov
Keyword(s):  
Heavy Metals ◽  
Cold Water ◽  
Arctic Lakes ◽  
Water Bodies ◽  
The Arctic ◽  
Anthropogenic Factors ◽  
Large Lakes ◽  
Arctic Water ◽  
The North ◽  
Natural And Anthropogenic Factors

Based on the study of the spatio-temporal aspects of the development of phytoplankton in the lakes of the North and North-West of the European territory of Russia (large lakes – Imandra, Onega and Chudsko-Pskovskoye and small lakes of the Arctic and Subarctic), the features of its structure and dynamics under the influence of natural and anthropogenic factors (eutrophication, heavy metal pollution, acidification, thermification). The species composition and quantitative characteristics of phytoplankton of large lakes of the North of Russia, small arctic lakes and lakes of subarctic regions are studied. It has been shown that diatoms predominate in arctic water bodies according to species diversity, and green and diatoms predominate in boreal ones. By biomass, diatoms dominate mainly in all cold-water lakes, with the exception of small arctic lakes, where golden algae lead. The features of the reorganization of phytoplankton in response to the action of anthropogenic factors are revealed. It is proved that in the northern water bodies the complex action of heavy metals and nutrients does not lead to inhibition of phytoplankton, and the effect of acidification in combination with heavy metals enhances the toxic effect of the latter. A feature of the response to acidification is an increase in the variability of the dynamics of the biomass of phytoplankton. It has been shown that in different types of lakes of East Antarctica under severe climate conditions under light and biogenic limitation, redistribution of autotrophic components in the formation of the biota of water bodies occurs: against the background of a decrease in the abundance and diversity of phytoplankton, the role of microphytobenthos and periphyton increases.

New data on the fauna and the biogeographic structure of the Hydrozoa, Scyphozoa, Staurozoa and Alcyonacea (Anthozoa) of the Kara Sea

2021 ◽  
Vol 325 (2) ◽  
pp. 143-155
Author(s):  
N.E. Zhuravleva
Keyword(s):  
Cold Water ◽  
Kara Sea ◽  
Novaya Zemlya ◽  
The North ◽  
Anna Trough ◽  
New Material ◽  
Western Side ◽  
Academy Of Sciences ◽  
North Western ◽  
Arctic Fauna

The paper considers the species composition of the fauna of several cnidarian groups of the Kara Sea. The author presents a list of species of the studied groups and indicates the types of habitat for each species. The analysis was based on the literature data, the collections of the Zoological Institute of the Russian Academy of Sciences and material collected in the Kara Sea during the expedition to the R/V Professor Multanovsky in 2019. In total, 87 species of Hydrozoa, 3 species of Scyphozoa, 4 species of Staurozoa, and 5 species of the order Alcyonacea from the class Anthozoa were recorded for the fauna of the Kara Sea, based on the new material obtained by the author and published literature data. The report presents the biogeographic structure of the discussed cnidarian groups. According to the types of biogeographic ranges, the fauna of the above-mentioned cnidarian groups in the Kara Sea mostly consists of representatives of the Boreal-Arctic type of habitat (63%), the Boreal and Amphiboreal biogeographic groups each containing 12% of the total number of described species, and the Panoceanic and Arctic groups together accounting for only 9% and 4% of the fauna of the Kara Sea. Two species new for the Kara Sea, Neoturris pileata (Forsskål, 1775) and Neoturris pileata (Forsskål, 1775), are described. Neoturris pileata is an element of the warm-water Atlantic fauna that penetrated into the Kara Sea with waters of Atlantic genesis. Nausithoe werneri is an element of the cold-water Arctic fauna that penetrated into the Novaya Zemlya Trough of the Kara Sea from the north-western side from the St. Anna Trough, which was open to the Polar Basin.

scholarly journals Ashinkailepas kermadecensis, a new species of deep-sea scalpelliform barnacle (Thoracica: Eolepadidae) from the Kermadec Islands, southwest Pacific

Zootaxa ◽  
2009 ◽  
Vol 2021 (1) ◽  
pp. 57-65 ◽  
Author(s):  
JOHN S. BUCKERIDGE
Keyword(s):  
New Species ◽  
New Zealand ◽  
Deep Sea ◽  
Cold Water ◽  
The Other ◽  
Cold Seeps ◽  
Central Japan ◽  
Southwest Pacific ◽  
The North ◽  
A New Species

A new deep-sea stalked barnacle, Ashinkailepas kermadecensis sp. nov. has been recovered from a cold-water seep at depths of 1165 metres in the vicinity of the Kermadec Ridge to the northeast of the North Island, New Zealand. There are now two species of Ashinkailepas—the other, Ashinkailepas seepiophila Yamaguchi, Newman & Hashimoto, 2004, occurs in deep, cold seeps off central Japan. As there are two species within Ashinkailepas, formal diagnoses are provided for both taxa.

scholarly journals HYDROCOOLING EFFICIENCY ON POSTHARVEST CONSERVATION AND QUALITY OF ARUGULA

2019 ◽  
Vol 6 (4) ◽  
pp. 36-41
Author(s):  
Elaine Gleice Silva Moreira ◽  
Scarlet Aguiar Basílio ◽  
Mariany Dalila Milan ◽  
Natália Arruda ◽  
Katiane Santiago Silva Benett
Keyword(s):  
Mass Loss ◽  
Respiratory Rate ◽  
Shelf Life ◽  
Water Loss ◽  
Cold Water ◽  
Subjective Evaluation ◽  
Storage Period ◽  
Titratable Acidity ◽  
Fresh Mass ◽  
Soluble Solids

Arugula is mainly cultivated by small producers, being a leafy vegetable susceptible to water loss and wilting after harvest, which may result in changes in appearance, texture, color (yellowing), and nutritional value of the product. Hydrocooling is a cooling method that stands out for being simple, practical and efficient. Its use is to reduce the temperature and respiratory rate of vegetables after harvesting by immersion in ice or cold water, so they can be packed and stored. This study was conducted to evaluate the hydrocooling efficiency when associated with the storage period in the postharvest shelf life of arugula leaves. Arugula leaves were subjected to ten days of storage, and measurements were taken at 0, 2, 4, 6, 8 and 10 days. The experimental design was completely randomized in a 3 × 6 factorial scheme, consisting of three hydrocooling treatments [control (without cooling), and hydrocooling at 0 °C and 10 °C] and for six storage periods (0, 2, 4, 6, 8 and 10 days) with three replicates. Fresh mass loss, soluble solids, titratable acidity, pH and subjective evaluation of product appearance were measured. Hydrocooling at 0 °C proved to be the most appropriate treatment when compared to control, as reported by the values of fresh mass loss, soluble solids, and titratable acidity. Hydrocooling to 0 °C slowed leaf water loss (lower respiratory rate) and resulted in better overall leaf appearance up to the sixth day of storage, thereby increasing shelf life of arugula leaves.

scholarly journals Report on hydrozoans (Cnidaria), excluding Stylasteridae, from the Emperor Seamounts, western North Pacific Ocean

Zootaxa ◽  
2021 ◽  
Vol 4950 (2) ◽  
pp. 201-247
Author(s):  
DALE R. CALDER ◽  
LES WATLING
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Western North Pacific ◽  
Cold Water ◽  
North Pacific Ocean ◽  
First Record ◽  
Western North Pacific Ocean ◽  
The North ◽  
Seamount Chain ◽  
The North Pacific

Fourteen species of hydroids, collected during August 2019 by ROV SuBastian of the Schmidt Ocean Institute, are reported from the Emperor Seamount chain in the western North Pacific Ocean. Two others, Candelabrum sp. and Eudendrium sp., were observed only on videos taken by the ROV. From collections and video observations, eight species of hydroids were found at Jingū Seamount, three at Yomei, Nintoku, and Annei seamounts, and one at Koko Seamount and Hess Rise. At Suiko and Godaigo seamounts, hydroids were seen in videos but they could not be identified. Latebrahydra schulzei, an endobiotic associate of the hexactinellid sponge Walteria flemmingii Schulze, 1886 from Annei Seamount and Hess Rise, is described as a new genus and species tentatively attributed to Hydractiniidae L. Agassiz, 1862. Another new species, Hydractinia galeai, is described from Jingū Seamount. Among its distinctive characters is a zooid termed a sellectozooid, likely serving in both food capture and defence. Hydroids examined from Yomei, Nintoku, and Jingū seamounts are elements of a cold-water fauna occurring in the North Pacific Boreal Bathyal province, while those of Annei and Koko seamounts, and Hess Rise, are part of the biota of the Central North Pacific Bathyal province. Hydroids identified as Bouillonia sp., from Nintoku Seamount, represent the first record of this predominantly deep water tubulariid genus in the North Pacific Ocean. Bonneviella superba Nutting, 1915, from Jingū Seamount, is reported for the first time outside the Aleutian Islands. Bonneviella cf. gracilis Fraser, 1939, known elsewhere only from Dease Strait in the western Canadian Arctic, was also collected on Jingū. In addition to hydroids, medusae of Ptychogastria polaris Allman, 1878 were observed on videos from Nintoku, Jingū, Annei, and Koko seamounts at depths between 2423–1422 m. An unidentified siphonophore was observed near bottom at 2282 m on Nintoku Seamount. 

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