Monitoring planktivorous seabird populations: validating surface counts of crevice-nesting auklets using mark–resight techniques

2006 ◽  
Vol 84 (6) ◽  
pp. 846-854 ◽  
Author(s):  
Lisa M. Sheffield ◽  
Adrian E. Gall ◽  
Daniel D. Roby ◽  
David B. Irons ◽  
Katie M. Dugger
Keyword(s):  
Bering Sea ◽  
Abundant Species ◽  
Density Estimates ◽  
Maximum Surface ◽  
Average Maximum ◽  
Aethia Pusilla ◽  
Secondary Productivity ◽  
Term Monitoring ◽  
The Bering Sea

Least Auklets ( Aethia pusilla (Pallas, 1811)) are the most abundant species of seabird in the Bering Sea and offer a relatively efficient means of monitoring secondary productivity in the marine environment. Counting auklets on surface plots is the primary method used to track changes in numbers of these crevice-nesters, but counts can be highly variable and may not be representative of the number of nesting individuals. We compared average maximum counts of Least Auklets on surface plots with density estimates based on mark–resight data at a colony on St. Lawrence Island, Alaska, during 2001–2004. Estimates of breeding auklet abundance from mark–resight averaged 8 times greater than those from maximum surface counts. Our results also indicate that average maximum surface counts are poor indicators of breeding auklet abundance and do not vary consistently with auklet nesting density across the breeding colony. Estimates of Least Auklet abundance from mark–resight were sufficiently precise to meet management goals for tracking changes in seabird populations. We recommend establishing multiple permanent banding plots for mark–resight studies on colonies selected for intensive long-term monitoring. Mark–resight is more likely to detect biologically significant changes in size of auklet breeding colonies than traditional surface count techniques.

scholarly journals Comparison of the Far-Eastern Seas and North-West Pacific by integral characteristics of pelagic and benthic trawled macrofaun

2014 ◽  
Vol 178 (3) ◽  
pp. 58-67
Author(s):  
Igor V. Volvenko
Keyword(s):  
Bering Sea ◽  
Large Scale ◽  
North West ◽  
The Pacific ◽  
Integral Characteristics ◽  
The Pacific Ocean ◽  
Far Eastern ◽  
Far Eastern Seas ◽  
The Bering Sea

The Bering Sea, ​​Okhotsk Sea, Japan/East Sea and adjacent waters of the Pacific Ocean (mainly within EEZ of Russia) are compared by abundance of pelagic and benthic macrofauna, its species richness, evenness, diversity, and mean weight of animals using the data of long-term large-scale pelagic and bottom trawl surveys conducted by Pacific Fish. Res. Center (TINRO) in 1977-2010.

scholarly journals BATTLING THE BERING SEA: ST GEORGE ISLAND’S BERM BREAKWATER

2018 ◽  
pp. 20
Author(s):  
Philip Blackmar ◽  
Ronald McPherson
Keyword(s):  
Bering Sea ◽  
Aleutian Island ◽  
Original Design ◽  
Winter Storm ◽  
Significant Damage ◽  
Project Site ◽  
Long Term Performance ◽  
Term Performance ◽  
The Bering Sea

St. George Island, Alaska is located in the Bering Sea more than 320 kilometers (200 miles) north of the nearest Aleutian Island. During original design and construction of the fishing harbor at St. George Island in the early 1980’s, stone large enough for a conventional breakwater was not available to quarry on the island, so the project utilized a berm breakwater approach with the available local stone. The long-term performance and service life of the berm breakwaters is reviewed in this paper. Construction of the berm breakwater was completed in 1987 and the breakwaters remained functional for nearly 20 years with little maintenance. In the winter of 2015/2016, approaching 30 years since initial construction, significant damage occurred during a winter storm. Repairs utilized a berm breakwater approach similar to the original design. Repairs were completed in 2 phases due to the short construction seasons at the project site.

scholarly journals Composition and structure of plankton communities in the Bering Sea

2021 ◽  
Vol 201 (1) ◽  
pp. 158-176
Author(s):  
K. M. Gorbatenko
Keyword(s):  
Deep Water ◽  
Bering Sea ◽  
Oithona Similis ◽  
Composition And Structure ◽  
Calanus Glacialis ◽  
Neocalanus Plumchrus ◽  
Calanus Marshallae ◽  
Metridia Pacifica ◽  
The Bering Sea

On the data of long-term surveys, mean biomass of plankton in the epipelagic layer of the Bering Sea is evaluated as 821.3 mg/m3 (1058.2 mg/m3 in shelf areas and 760.6 mg/m3 in the deep-water areas) and the stock as 245.1•106 t WW (64.4 • 106 t over the shelf and 180.7 • 106 t in the deep-water sea). By taxa, the average annual portions are: 55.1 % for copepods, 26.3 % for arrowworms, 10.8 % for euphausiids, 3.2 % for medusas, and 2.9 % for amphipods. The dominant species are the arrowworm Sagitta elegans (26.3 %) and the copepod Eucalanus bungii (19.7 %); other mass species are: large-sized copepods Neocalanus cristatus (10.4 %), Neocalanus plumchrus + Neocalanus flemingeri (7.8 %) and Calanus glacialis + Calanus marshallae (5.1 %), euphausiids Thysanoessa raschii (3.5 %) and Thysanoessa longipes (3.4 %), small-sized copepods Metridia pacifica (3.5 %) and Oithona similis (3.5 %), medusa Aglantha digitale (3.2 %).

scholarly journals Effects of handling and short-term captivity: a multi-behaviour approach using red sea urchins, Mesocentrotus franciscanus

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6556 ◽  
Author(s):  
Aneesh P.H. Bose ◽  
Daniel Zayonc ◽  
Nikolaos Avrantinis ◽  
Natasha Ficzycz ◽  
Jonathan Fischer-Rush ◽  
...  
Keyword(s):  
Red Sea ◽  
Sea Urchins ◽  
Abundant Species ◽  
Ecosystem Functions ◽  
Short Term ◽  
Induced Stress ◽  
Aggregation Behaviour ◽  
Fitness Consequences ◽  
Term Monitoring

Understanding the effects of captivity-induced stress on wild-caught animals after their release back into the wild is critical for the long-term success of relocation and reintroduction programs. To date, most of the research on captivity stress has focused on vertebrates, with far less attention paid to invertebrates. Here, we examine the effect of short-term captivity (i.e., up to four days) on self-righting, aggregation, and predator-escape behaviours in wild-caught red sea urchins, Mesocentrotus franciscanus, after their release back into the wild. Aggregation behaviour, which has been linked to feeding in sea urchins, was not affected by handling or captivity. In contrast, the sea urchins that had been handled and released immediately, as well as those that were handled and held captive, took longer to right themselves and were poorer at fleeing from predators than wild, unhandled sea urchins. These results indicate that handling rather than captivity impaired these behaviours in the short term. The duration of captivity did not influence the sea urchin behaviours examined. Longer-term monitoring is needed to establish what the fitness consequences of these short-term behavioural changes might be. Our study nevertheless highlights the importance of considering a suite of responses when examining the effects of capture and captivity. Our findings, which are based on a locally abundant species, can inform translocation efforts aimed at bolstering populations of ecologically similar but depleted invertebrate species to retain or restore important ecosystem functions.

scholarly journals Variability of ice conditions of the Bering sea and assessment of the possibility of their modelling

2019 ◽  
Vol 59 (6) ◽  
pp. 920-927
Author(s):  
V. V. Plotnikov ◽  
N. M. Vakulskaya ◽  
V. A. Dubina
Keyword(s):  
Sea Ice ◽  
Interannual Variability ◽  
Bering Sea ◽  
Ice Cover ◽  
Practical Application ◽  
Seasonal And Interannual Variability ◽  
Proposed Model ◽  
Ice Conditions ◽  
The Bering Sea

Various aspects of seasonal and interannual variability of the sea ice cover are estimated on the basis of all available the Bering Sea ice data from 1960 to 2017. The possibility of long-term and superlong-term modeling of the ice cover is investigated. Results of tests are given, and a conclusion about prospects of the proposed model and an opportunity of its practical application is done.

scholarly journals Long-term dynamics of stocks of greenland halibut Reinhardtius hippoglossoides matsuurae in the Bering Sea and Pacifc waters at Kamchatka and Kuril Islands

2018 ◽  
Vol 195 ◽  
pp. 28-47
Author(s):  
A. O. Zolotov ◽  
O. A. Maznikova ◽  
A. Yu. Dubinina
Keyword(s):  
Continental Slope ◽  
Bering Sea ◽  
Kuril Islands ◽  
Greenland Halibut ◽  
Eastern Kamchatka ◽  
The North ◽  
Western Bering Sea ◽  
Northern Kuril Islands ◽  
The Bering Sea

Despite the long history of studies, some aspects of the greenland halibut biology in the North Pacifc are still poorly known. In particular, scientifc publications on its groupings in the Bering Sea and at the continental slope of the North Pacifc and their dynamics are rather few, with exception of the western Bering Sea area from Cape Olyutorsky to the Anadyr Bay where its dynamics is well traced by surveys of Pacifc Fish. Res. Center (TINRO). All data on long-term dynamics of the greenland halibut abundance and distribution in the Bering Sea and Pacifc waters at Kamchatka and Kuril Islands are overviewed and comparatively analyzed, including materials of bottom trawl surveys conducted in 1950–2015 and published research reports, in total the data of 66 surveys (4,350 bottom trawls) in the Karaginsky and Olyutorsky Bays, 43 surveys (4,900 trawls) on the Pacifc shelf and continental slope of Kamchatka and northern Kuril Islands, and 24 surveys (2,048 trawls) at southern Kuril Islands. Biomass of greenland halibut is assessed for the western Bering Sea and the Pacifc waters at Kamchatka and the Kuriles using the data of TINRO and for the eastern Bering Sea using the published data of NOAA and NPFMC. Gradual decreasing of commercial value of the halibut groups is shown with increase of the distance from its main spawning grounds in the southeastern Bering Sea. Self-reproduction of the halibut groups supposedly decreases in the same direction. This assumption is confrmed by the data on its larvae and juveniles density in the epipelagic layer of the western Bering Sea and North-West Pacifc that decreases from the maximum values in the Anadyr Bay to the Olyutorsko-Navarinsky district and further southward to the minimum value at southern Kuril Islands. The average portions of certain groups of greenland halibut in its total biomass in the North Pacifc (without the Okhotsk Sea) are estimated as follows: almost 85 % (146.0 . 103 t) is contributed by the southeastern Bering Sea, about 14 % (23.2 . 103 t) — by Olyutorsko-Navarinsky district and the Anadyr Bay, and 1% (about 1.5 . 103 t) — by the waters at northeastern and eastern Kamchatka and at Kuril Islands. Stock dynamics is similar for all groups: the stocks increased until the early 1970s with the peak in 1976–1980, when the species biomass was estimated as 280 . 103 t in the southwestern Bering Sea, 40 . 103 t in the Anadyr Bay and Olyutorsko-Navarinsky district, and 5 . 103 t in the bays of eastern Kamchatka and at northern Kuril Islands, then declined to the minimum in 1990–2000s, and recently the peripheral groups show a gradual growth. The dynamics similarity is possibly reasoned by passive transfer of the halibut eggs and larvae from the Bering Sea toward eastern Kamchatka and Kuril Islands by the system of oceanic currents.

scholarly journals A long-term study of a snake community in north-western Tuscany (central Italy): population structure and density patterns

Herpetozoa ◽  
2019 ◽  
Vol 32 ◽  
pp. 101-107
Author(s):  
Federico Storniolo ◽  
Sacha Menichelli ◽  
Marco A.L. Zuffi
Keyword(s):  
Western Europe ◽  
Central Italy ◽  
Short Term ◽  
Density Estimates ◽  
Snake Species ◽  
Long Term Study ◽  
Term Monitoring ◽  
North Western ◽  
Average Body

We analysed a snake species community of a Mediterranean 0.2 ha ecotonal area during a 21 year time span, monitoring two colubrid and one viperid snake species. We carried out analyses in seven years (1997, 1999, 2002, 2004–2005, 2016–2017) that had similar sampling efforts and, in the last two years of short-term monitoring, we applied a recently proposed monitoring protocol of the Italian Environment Ministry. In total, we captured 172 distinct individuals, 61 whip snakes (Hierophisviridiflavus), 26 barred grass snakes (Natrixhelvetica) and 85 asp vipers (Viperaaspis). Regarding the long-term monitoring period, whip snakes were captured on average about nine times per year, grass snakes were captured four times per year and asp vipers were found 12 times per year. Captures decreased in whip snakes, while increased in grass snakes and remained constant in asp vipers. In 2016 and 2017, we captured 10 whip snakes, 19 grass snakes and 31 asp vipers. Density estimates of snake species (0.5 H.viridiflavus/ha, 0.3 N.helvetica/ha and 0.7 V.aspis/ha) differ, to a certain extent, from published results for some other areas of central, northern and western Europe, perhaps depending on the approach applied for habitat suitability estimation. The average body size between two years differed neither for whip snakes nor for grass snakes, but it decreased significantly in asp vipers.

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