Skate <i>Bathyraja</i> spp. egg predation in the eastern Bering Sea

Hoff, Gerald R.

doi:10.1111/j.1095-8649.2008.02137.x

Cited by 32 publications

(43 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The abundant prey also may explain the high biomass and diversity of skate species and the presence of other large predatory fish species such as Pacific cod, Pacific halibut and arrowtooth flounder Atheresthes stomias found at nursery sites. Skate embryo development time is correlated with water temperature (Berestovskii 1994, Hoff 2007, 2008 and shorter development times may increase recruitment potential through decreased exposure to predation (Hoff 2007(Hoff , 2008(Hoff , 2009b and greater hatching success. The upper slope environment has relatively warm and stable average annual bottom temperatures when compared with the whole EBS.…”

Section: Discussionmentioning

confidence: 99%

Identification of skate nursery habitat in the eastern Bering Sea

Hoff

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Identification of habitat used for skate egg deposition has been rarely studied or reported worldwide. Four nursery sites for the Alaska skate Bathyraja parmifera, 2 for the Aleutian skate B. aleutica and 2 for the Bering skate B. interrupta were identified along the upper continental slope in the eastern Bering Sea. All sites were located near undersea canyons from 145 to 380 m depth in relatively flat sandy to muddy bottom habitat. Bottom temperatures were relatively constant throughout the year, varying from 3.7 to 4.6°C. Egg case densities varied between nursery sites and were encountered at the Alaska skate nursery in Bering Canyon at densities greater than 800 000 eggs km -2 . Based on egg case composition, sites were predominantly used by a single skate species for egg deposition; however, up to 6 skate species used the habitat commonly. Seasonal sampling indicated that sites were continuously occupied throughout the year, and embryo length composition showed multiple cohorts developing simultaneously. Data from bottom trawl surveys suggest juvenile skates occupy habitats different than nursery sites. The movement of juvenile skates out of nursery habitat after hatching may lessen predation by common predators such as the Pacific cod Gadus macrocephalus and the Pacific halibut Hippoglossus stenolepis.KEY WORDS: Elasmobranch · Skate · Reproduction · Egg case · Undersea canyon · Nursery · Alaska Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 403: [243][244][245][246][247][248][249][250][251][252][253][254] 2010 Lauth & Acuna 2009). Combined these 3 species constitute > 95% of the skate population and biomass in the entire EBS (20 to 1200 m depth) and are the major components of skate bycatch in non-target commercial bottom trawl and longline fisheries (Stevenson 2004). Other important slope-dwelling species in the EBS include the whiteblotched skate B. maculata, the mud skate B. taranetzi, the Commander skate B. lindbergi and the whitebrow skate B. minispinosa (Hoff & Britt 2009).This study focuses on identification of skate nursery habitat for 3 abundant skate species in the eastern Bering Sea. Four nursery sites for the Alaska skate, 2 nursery sites for the Aleutian skate, and 2 nursery sites for the Bering skate ( Fig. 1) are described. Some important biological aspects examined were skate and skate egg case composition, egg case densities and predation on juvenile skates. Nursery habitat parameters include location, temporal use, depth, temperature, bottom topography and associated sessile fauna EasternBering SeaGulf of Alaska P e rv e n e ts C a n y o n P r ib il o f C a n y o n B e r in g C a n y o n MATERIALS AND METHODSNursery habitat identification. Initial locations of nursery sites were identified based on fisheries data, and previous survey trawls in which large numbers of skate egg cases were reported in the catch. Identified sites were subsequently sampled using bottom trawls in an adaptive sampling approach to identify the egg...

show abstract

Section: Discussionmentioning

confidence: 99%

Identification of skate nursery habitat in the eastern Bering Sea

Hoff

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Smale et al 2001), but the egg masses themselves may also provide temporary habitat for some organisms. The skates (Family Rajidae) spawn in areas where hatched or depredated egg cases accumulate in the sediment, and attract invertebrate predators (Hoff 2009). The extent to which this habitat is important to other species aside from egg predators is unknown.…”

Section: Discussionmentioning

confidence: 99%

<em>Octopus tetricus</em> (Mollusca: Cephalopoda) as an ecosystem engineer

Scheel¹,

Godfrey‐Smith²,

Lawrence³

2014

Sci. Mar.

View full text Add to dashboard Cite

Summary:The Sydney octopus (Octopus tetricus) occurs in unusual numbers on a shell bed of its prey remains that have accumulated as an extended midden where additional octopuses excavate dens. Here, O tetricus are ecosystem engineers, organisms that modulate availability of resources to other species and to their own species by causing physical state changes in materials. A community of invertebrate grazers and scavengers has developed on the shell bed. Fishes are attracted to the shell bed in numbers significantly greater than in nearby habitats. Large predators, including wobbegong sharks, were attracted to and fed on concentrations of fish, inhibiting the activities of the original engineers, the octopuses. Positive feedbacks included the accumulation of shell debris, increasing shelter availability for additional octopuses and aggregating fish. Negative feedbacks included reductions of nearby prey size and availability, aggression among octopuses, and predator limitation to octopus activity that would otherwise maintain the shell bed.Keywords: Jervis Bay; social; population density; denning; aggregation. Octopus tetricus (Mollusca: Cephalopoda) como ingeniero de ecosistemasResumen: El pulpo Sydney (Octopus tetricus) aparece en cantidades inusuales en un fondo de cascajo producido por los restos de sus presas que se han acumulado como un extenso estercolero donde otros pulpos excavan sus guaridas. Aquí, O. tetricus se comportan como ingenieros del ecosistema, organismos que modulan la disponibilidad de recursos a otras especies y su propia especie provocando cambios físicos en los materiales. Una comunidad de invertebrados herbívoros y carroñeros se desarrolló en el fondo de cascajo. Los peces son atraídos a dicho fondo en número significativamente mayor que en hábitats cercanos. Grandes depredadores, como los tiburones wobbegong son atraídos y se alimentan a partir de concentraciones de peces inhibiendo las actividades originales de los ingenieros de los pulpos. La reacción positiva a la acumulación de escombros incrementa la disponibilidad de refugio para los otros pulpos y la concentración de peces. Los efectos negativos incluyen la reducción de la disponibilidad y el tamaño de los peces, la agresión entre los pulpos, y la limitación de la actividad de los pulpos para mantener el fondo de cascajo como resultado de la presencia de depredadores.

show abstract

“…The results reported herein indicate that density-dependent compensation in the form of increased egg case survival would not substantially increase λ , particularly for B. lindbergi , B. maculata , and B. minispinosa . Additionally, there is evidence that embryonic survival during the egg case stage is positively correlated with density in skates [44], making increased egg case survival an even less likely compensation mechanism. In contrast, ratios of adult to juvenile survival indicate that compensation is more likely to occur through increased juvenile survival due to reduced intraspecific competition at lower population densities.…”

Section: Discussionmentioning

confidence: 99%

“…Embryo survival was represented by empirical estimates of egg-case predation rates in the EBS [43], [44]. Direct estimates were available for only two of the five species, B. taranetzi and B. trachura .…”

Section: Methodsmentioning

confidence: 99%

Comparative Demography of Skates: Life-History Correlates of Productivity and Implications for Management

et al. 2013

View full text Add to dashboard Cite

Age-structured demographic models were constructed based on empirical estimates of longevity and maturity for five deepwater Bering Sea skates to investigate how observed differences in life history parameters affect population growth rates. Monte Carlo simulations were used to incorporate parameter uncertainty. Estimated population growth rates ranged from 1.045 to 1.129 yr−1 and were lower than those reported for other Alaskan skates and most chondrichthyans. Population growth rates of these and other high-latitude skates increased with relative reproductive lifespan, but displayed no significant relationship with body size or depth distribution, suggesting that assemblage shifts may be difficult to predict for data-poor taxa. Elasticity analyses indicated that juvenile and adult survival had greater per-unit effects on population growth rates than did egg-case survival or fecundity. Population growth rate was affected more by uncertainty in age at maturity than maximum age. The results of this study indicate that if skates are deemed to be a management concern, gear modifications or depth-specific effort controls may be effective.

show abstract

Skate Bathyraja spp. egg predation in the eastern Bering Sea

Cited by 32 publications

References 18 publications

Identification of skate nursery habitat in the eastern Bering Sea

Identification of skate nursery habitat in the eastern Bering Sea

<em>Octopus tetricus</em> (Mollusca: Cephalopoda) as an ecosystem engineer

Comparative Demography of Skates: Life-History Correlates of Productivity and Implications for Management

Contact Info

Product

Resources

About