scholarly journals Assessing the ecological importance of red tree coral thickets in the eastern Gulf of Alaska

2014 ◽  
Vol 72 (3) ◽  
pp. 900-915 ◽  
Author(s):  
Robert P. Stone ◽  
Michele M. Masuda ◽  
John F. Karinen
Keyword(s):  
North Pacific Ocean ◽  
Fish Habitat ◽  
Keystone Species ◽  
Gulf Of Alaska ◽  
Habitat Characteristics ◽  
Benthic Habitat ◽  
Logistic Regression Models ◽  
Small Areas ◽  
Bottom Contact ◽  
The North

Abstract Red tree corals (Primnoa pacifica), the largest structure-forming gorgonians in the North Pacific Ocean, form dense thickets in some areas. These thickets are a dominant benthic habitat feature in the Gulf of Alaska (GOA), yet little is known about the ecosystems they support. In 2005, we used a submersible to study the ecology of thickets inside or near five small areas of the eastern GOA later designated in 2006 as habitat areas of particular concern (HAPCs)―areas closed to all bottom contact fishing. We show that red tree corals are keystone species in habitats where they form thickets (mean density 0.52 corals m−2)—the densest and largest thickets documented anywhere. Measured sponge densities (2.51 sponges m−2) were also among the highest documented anywhere. The corals and sponges in the study areas provide essential fish habitat for some fish species, and we show with logistic regression models modified with a scaled binomial variance that bedrock, while important habitat for some fish, is even more important when paired with corals and sponges. Red tree corals were not equally distributed with regard to habitat characteristics, and we show that their presence was correlated with bedrock substrate, moderate to high seabed roughness, and slope >10°. Most corals and sponges are vulnerable to disturbance from longlining, the principal bottom contact fishing in this region, but the larger corals and sponges are the most vulnerable. We observed evidence of infrequent recruitment events and a strong pulse of predation, apparently from fishing gear-induced trauma, that could exacerbate slow recovery of red tree corals from disturbance. Some red tree coral thickets are provided protection within designated HAPCs and some are not. Modifications to longline gear and an expanded network of HAPCs could help preserve these keystone species and the ecosystems they support.

Biology of the Pacific Pomfret (Brama japonica) in the North Pacific Ocean

1993 ◽  
Vol 50 (12) ◽  
pp. 2608-2625 ◽  
Author(s):  
William G. Pearcy ◽  
Joseph P. Fisher ◽  
Mary M. Yoklavich
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Gulf Of Alaska ◽  
Small Fish ◽  
Large Fish ◽  
The North ◽  
The Pacific ◽  
Subarctic Current ◽  
The North Pacific

Abundances of Pacific pomfret (Brama japonica), an epipelagic fish of the North Pacific Ocean, were estimated from gillnet catches during the summers of 1978–1989. Two size modes were common: small pomfret <1 yr old, and large fish ages 1–6. Large and small fish moved northward as temperatures increased, but large fish migrated farther north, often into the cool, low-salinity waters of the Central Subarctic Pacific. Lengths of small fish were positively correlated with latitude and negatively correlated with summer surface temperature. Interannual variations in the latitude of catches correlated with surface temperatures. Large catches were made in the eastern Gulf of Alaska (51–55°N) but modes of small pomfret were absent here, and large fish were rare at these latitudes farther to the west. Pomfret grow rapidly during their first two years of life. They are pectoral fin swimmers that swim continuously. They prey largely on gonatid squids in the region of the Subarctic Current in the Gulf of Alaska during summer. No evidence was found for aggregations on a scale ≤1 km. Differences in the incidence of tapeworm, spawning seasons, and size distributions suggest the possibility of discrete populations in the North Pacific Ocean.

Serpulidae (Annelida, Polychaeta) from Patton-Murray Seamounts, Gulf of Alaska, North Pacific Ocean

Zootaxa ◽  
2010 ◽  
Vol 2665 (1) ◽  
pp. 51 ◽  
Author(s):  
ELENA K. KUPRIYANOVA ◽  
EIJIROH NISHI
Keyword(s):  
Sequence Data ◽  
North Pacific Ocean ◽  
Gulf Of Alaska ◽  
Sister Group ◽  
Maximum Parsimony Analysis ◽  
Phylogenetic Position ◽  
Data Set ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
The North

A collection of Serpulidae (Annelida, Polychaeta) from the Patton-Murray Seamounts, Gulf of Alaska, USA contained three species Apomatus voightae n. sp., Bathyvermilia eliasoni n. comb., and Hyalopomatus biformis (Hartman, 1960). Apomatus voightae n. sp. differed from all other Apomatus spp. and from all known serpulid species by very unusual flat and ribbon-like branchial radioles as well by details of chaetal structure. Vermiliopsis eliasoni Zibrowius (1970) previously known from Atlantic and Mediterranean, was transferred to the genus Bathyvermilia Zibrowius, 1973. Hyalopomatus biformis is a deep-sea species distributed in the north-eastern Pacific from Alaska to California, USA. All serpulids were described in detail and their chaetal structure elucidated with the help of scanning electron microscopy. Molecular sequence data (18S rDNA) were aligned to a recently published serpulid data set and maximum parsimony analysis was performed to examine the phylogenetic position of the species and confirm their identification. Hyalopomatus biformis formed a sister group with Laminatubus alvini, Apomatus voightae n. sp. formed a sister group with Apomatus globifer, and Bathyvermilia eliasoni formed a weakly supported polytomy with Chitinopoma serrula, Protula tubularia and Apomatus spp. We briefly discussed biogeographic affinities of the serpulids from the PattonMurray Seamounts in the light of seamount ecology and biogeography.

Incorporation of bomb-produced14C into fish otoliths. An example of basin-specific rates from the North Pacific Ocean

2015 ◽  
Vol 72 (6) ◽  
pp. 879-892 ◽  
Author(s):  
Stephen G. Wischniowski ◽  
Craig R. Kastelle ◽  
Timothy Loher ◽  
Thomas E. Helser
Keyword(s):  
North Pacific Ocean ◽  
Deviance Information Criterion ◽  
Information Criterion ◽  
Gulf Of Alaska ◽  
Estimation Accuracy ◽  
Model Parameters ◽  
Age Validation ◽  
The North ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis

Sagittal otoliths from juvenile Pacific halibut (Hippoglossus stenolepis) of known age were used to create a bomb-produced radiocarbon reference chronology for the eastern Bering Sea (EBS) by fitting a coupled-function model to Δ14C values from each specimen’s birth year. The newly created EBS reference chronology was then compared with a reference chronology previously created for Pacific halibut from the Gulf of Alaska (GOA). Adult Pacific halibut age-validation samples from the EBS were also analyzed for14C and modeled to validate age-estimation accuracy. A Bayesian model was developed and Markov chain Monte Carlo simulation was used to estimate model parameters and adult Pacific halibut ageing bias. Differences in reference chronologies between ocean basins were reflected in a large deviance information criterion (ΔDIC) between models, supporting the hypothesis that two separate coupled-function models were required to adequately describe the data, one each for the EBS and GOA. We determined that regionally specific GOA and EBS oceanography plays a considerable role in the Δ14C values and must be taken into consideration when selecting a reference chronology for bomb-produced14C age-validation studies. The age-validation samples indicated that the current ageing methodology used in Pacific halibut assessments is accurate and has provided accurate age assignments for Pacific halibut in the EBS.

Histodermella kagigunensis sp. nov. from the Gulf of Alaska and Aleutian Islands; first records of the genus from the North Pacific

2012 ◽  
Vol 93 (5) ◽  
pp. 1245-1248
Author(s):  
Helmut Lehnert ◽  
Robert P. Stone ◽  
Wolfgang Heimler
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Gulf Of Alaska ◽  
First Record ◽  
Aleutian Islands ◽  
The North ◽  
The North Pacific

The genus Histodermella grows to four species with the addition of H. kagigunensis sp. nov. from the North Pacific. The new species is described and compared with all congeners. Histodermella kagigunensis shows affinities to H. ingolfi Lundbeck 1910 as it has the same spicule types but differs clearly in size, habitus and the dimensions of two occurring spicule types. The discovery of H. kagigunensis represents the first record of the genus Histodermella in the North Pacific Ocean.

Examining the links between multi-frequency backscatter, geomorphology and benthic habitat associations in Marine Protected Areas

2020 ◽  
Author(s):  
Robert Mzungu Runya ◽  
Chris McGonigle ◽  
Rory Quinn
Keyword(s):  
Marine Protected Area ◽  
Explanatory Power ◽  
Habitat Associations ◽  
Habitat Characteristics ◽  
Single Frequency ◽  
North Coast ◽  
Benthic Habitat ◽  
Infaunal Community ◽  
The North ◽  
Marine Habitats

&lt;p&gt;Acoustic methods are frequently used to provide broad-scale information on the spatial extent, range and distribution of marine habitats and sedimentary environments. Although single frequency multibeam echosounders have dominated seabed mapping for decades, multi-frequency approaches are starting to present in the scientific literature. Multibeam survey strategies are generally optimized for the acquisition of bathymetry data, often overlooking the ecological and geological value of backscatter data. This study examines the benefits of combining multi-frequency backscatter responses to discriminate seabed properties in areas with strong geomorphological gradients and associated ecological variability. The frequency-dependence element of backscatter strength is linked to: (i) the dominant scattering regime, (ii) seabed roughness, and (iii) the input of volume scattering related to signal penetration. In 2019, we collected and analyzed multifrequency (200, 95 and 30-kHz) backscatter data from Hempton&amp;#8217;s Turbot Bank, a marine protected area off the north coast of Ireland. We compare these data with legacy 300 kHz backscatter data from 2013 to explore the backscatter variability in the context of geomorphological change. We assess the explanatory power of multi-frequency vis-&amp;#224;-vis single-frequency backscatter data in terms of bathymetry, sediment granulometry and infaunal community structure. Results improve our understanding of the link between backscatter properties and geomorphology, with specific recommendations towards minimizing information loss and establishing minimum data requirements for frequency-based benthic habitat discrimination. Improved discrimination of geomorphology and benthic habitat characteristics enhances the reliability of backscatter data as a monitoring technique for area-based protection of marine resources.&lt;/p&gt;

Description of a new species of Trichogypsiidae (Porifera, Calcarea) and first record of the genus in the Pacific Ocean

Zootaxa ◽  
2017 ◽  
Vol 4312 (2) ◽  
pp. 394 ◽  
Author(s):  
HELMUT LEHNERT ◽  
ROBERT P. STONE
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
North Pacific Ocean ◽  
Gulf Of Alaska ◽  
First Record ◽  
The North ◽  
The Pacific ◽  
The Family ◽  
The Pacific Ocean ◽  
A New Species

A new species of Trichogypsiidae is described and compared to its congeners. Trichogypsia alaskensis n. sp. represents the fifth species of the family and with this record all three genera of the family are now represented in the North Pacific Ocean. Calcarea are rare in the Gulf of Alaska but with this new record the number of confirmed species rises from two to three. The new species has larger diactines of a broader size range and with a different pattern of spination than all congeners. 

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