Alaskan Observers Inc.

Town and Country, WA, United States

Alaskan Observers Inc.

Town and Country, WA, United States
SEARCH FILTERS
Time filter
Source Type

Barord G.J.,Gulf Marine Institute of Technology | Barord G.J.,Alaskan Observers Inc. | Keister K.N.,Gulf Marine Institute of Technology | Lee P.G.,Gulf Marine Institute of Technology
Aquaculture International | Year: 2010

The purpose of this experiment was to observe the impact of stocking density on growth and food consumption of juvenile Sepia pharaonis reared at 23 and 28°C. Two groups of 32 cuttlefish each were reared in closed recirculating seawater systems with water temperatures of 23°C (group A) and 28°C (group B). Each group was divided into three treatments with two replicates per treatment: low-density (equivalent to 20 cuttlefish m-2), medium-density (equivalent to 100 cuttlefish m-2), and high-density (equivalent to 200 cuttlefish m-2). Measured amounts of live food were added three times a day and the wet body weight of each cuttlefish was measured once a week during the 42-day study. Cuttlefish in group B had higher growth rates and food consumption than cuttlefish in group A. The different stocking densities in group B affected the size of the cuttlefish whereas the stocking densities of the cuttlefish in group A treatments did not lead to different sizes between densities. Overall, the gross growth efficiency of the high-density treatments was lower than that of the low-density treatments, as was the weight of the cuttlefish in the high-density treatment. Although the wet weights of group A treatments were not significantly different (P > 0. 05), the wet weights of the cuttlefish in the high-density, group B, treatment were lower than those in the low and medium density treatments. This decrease in individual size suggests that stocking densities of 100 to 200 cuttlefish m-2 may interfere with growth. © 2009 Springer Science+Business Media B.V.


Roosenburg W.M.,Ohio University | Spontak D.M.,Ohio University | Sullivan S.P.,Alaskan Observers Inc. | Matthews E.L.,Ohio University | And 6 more authors.
Restoration Ecology | Year: 2014

Aquatic turtles worldwide are plagued with habitat loss due to development and shoreline alteration that destroys the terrestrial-aquatic linkage which they must cross to reproduce successfully. Furthermore, nesting habitat loss can concentrate nesting, increasing nest predator efficiency. We describe how the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island created nesting habitat for Malaclemys terrapin (Diamondback Terrapin), and document nesting success in response to construction progress and the absence of raccoons and foxes, the primary nest predators. We monitored terrapin nests throughout the nesting seasons from 2002 to 2011 to determine overall and within-nest survivorship. Female terrapins began nesting on the restoration project within 1year but planned construction during the study eliminated some nesting areas and opened previously inaccessible areas. Overall, nest survivorship was considerably higher than mainland nesting areas due to the absence of raccoons and foxes on the island and within-nest survivorship was similar. Egg size, hatchling size, and the frequency of shell scute anomalies were similar to other terrapin populations, suggesting normal developmental conditions on the island. We documented annual variation in hatchling size that correlated negatively with mean air temperature during the incubation season. Our results indicate that restored or created isolated island habitat can be located rapidly by terrapins and can become an important source of recruitment in regions where nesting habitat is limited and predation is high. Poplar Island illustrates how habitat loss and restoration can affect turtle populations by revealing the changes in nesting patterns and success in newly created, predator-free habitat. © 2014 Society for Ecological Restoration.


Roosenburg W.M.,Ohio University | Spontak D.M.,Ohio University | Sullivan S.P.,Alaskan Observers Inc. | Matthews E.L.,Ohio University | And 6 more authors.
Restoration Ecology | Year: 2014

Aquatic turtles worldwide are plagued with habitat loss due to development and shoreline alteration that destroys the terrestrial-aquatic linkage which they must cross to reproduce successfully. Furthermore, nesting habitat loss can concentrate nesting, increasing nest predator efficiency. We describe how the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island created nesting habitat for Malaclemys terrapin (Diamondback Terrapin), and document nesting success in response to construction progress and the absence of raccoons and foxes, the primary nest predators. We monitored terrapin nests throughout the nesting seasons from 2002 to 2011 to determine overall and within-nest survivorship. Female terrapins began nesting on the restoration project within 1 year but planned construction during the study eliminated some nesting areas and opened previously inaccessible areas. Overall, nest survivorship was considerably higher than mainland nesting areas due to the absence of raccoons and foxes on the island and within-nest survivorship was similar. Egg size, hatchling size, and the frequency of shell scute anomalies were similar to other terrapin populations, suggesting normal developmental conditions on the island. We documented annual variation in hatchling size that correlated negatively with mean air temperature during the incubation season. Our results indicate that restored or created isolated island habitat can be located rapidly by terrapins and can become an important source of recruitment in regions where nesting habitat is limited and predation is high. Poplar Island illustrates how habitat loss and restoration can affect turtle populations by revealing the changes in nesting patterns and success in newly created, predator-free habitat. © 2014 Society for Ecological Restoration.


Hannah R.W.,Hatfield Marine Science Center | Jones S.A.,Hatfield Marine Science Center | Miller W.,Hatfield Marine Science Center | Knight J.S.,Alaskan Observers Inc.
Fishery Bulletin | Year: 2010

Surveys with a remotely operated vehicle (ROV) at four mudhabitat sites with different histories of ocean shrimp (Pandalus jordani) trawling showed measurable effects of trawling on macroinvertebrate abundance and diversity. Densities of the sea whip (Halipteris spp., P<0.01), the flat mud star (Luidia foliolata, P<0.001), unidentified Asteroidea (P<0.05), and squat lobsters (unidentified Galathoidea, P<0.001) were lower at heavily trawled (HT) sites, as was invertebrate diversity based on the Shannon-Wiener index. Sea cucumbers (unidentified Holothuroidea) and unidentified corals (Hydrocoralia) were observed at lightly trawled (LT) sites but not at HT sites. Hagfish (Eptatretus spp.) burrows were the dominant structural feature of the sediment surface at all sites and were more abundant at the HT sites (P<0.05), a result potentially related to effects from fishery discards. Substantial heterogeneity was found between the northern and southern site pairs, indicating high site-to-site variability in macroinvertebrate densities in these deep (146-156 m) mud habitats. Two of the study sites were closed to trawling in June 2006. The data from this study can be used in combination with future surveys to measure recovery rates of deep, mud, seafloor habitats from the effects of trawling, thus providing a critical piece of information for ecosystem-based management.

Loading Alaskan Observers Inc. collaborators
Loading Alaskan Observers Inc. collaborators