Max K. Hoberg

Exposure to hydrocarbons 10 years after the Exxon Valdez oil spill: evidence from cytochrome P4501A expression and biliary FACs in nearshore demersal fishes

Three biomarkers of hydrocarbon exposure, CYP1A in liver vascular endothelium, liver ethoxyresorufin O-deethylase (EROD), and biliary fluorescent aromatic compounds (FACs), were examined in the nearshore fishes, masked greenling (Hexagrammos octogrammus) and crescent gunnel (Pholis laeta), collected in Prince William Sound, Alaska, 7-10 years after the Exxon Valdez oil spill (EVOS). All biomarkers were elevated in fish collected from sites originally oiled, in comparison to fish from unoiled sites. In 1998, endothelial CYP1A in masked greenling from sites that were heavily oiled in 1989 was significantly higher than in fish collected outside the spill trajectory. In 1999, fishes collected from sites adjacent to intertidal mussel beds containing lingering Exxon Valdez oil had elevated endothelial CYP1A and EROD, and high concentrations of biliary FACs. Fishes from sites near unoiled mussel beds, but within the original spill trajectory, also showed evidence of hydrocarbon exposure, although there were no correlations between sediment petroleum hydrocarbon and any of the biomarkers. Our data show that 10 years after the spill, nearshore fishes within the original spill zone were still exposed to residual EVOS hydrocarbons.

Temporal variability of benthic communities in an Alaskan glacial fjord, 1971–2007

Temporal trends of deep-subtidal macrofauna in Port Valdez, Alaska, were assessed with respect to multiple environmental stressors. Effects from a magnitude 9.2 earthquake in Prince William Sound, Alaska, 1964, were reflected in recolonization of the basin of the fjord, increased abundance and number of taxa over time, and moderately increased variability in abundance through 1990, stabilizing 26years after the earthquake. Long-term climatic variability and local physical processes were important sources of spatial and temporal variability. Correlative evidence suggests that indirect effects of juvenile salmon from a shoreline salmon hatchery and deposition of adult salmon carcasses moderately enhanced deep-basin benthic communities. Effects on the deep benthos from a marine oil terminal were negligible. Overall, faunal trends deviated from the stability expected for benthic communities in other fjords. Physical characteristics of the fjord were important in mediating the effects of stressors and in delaying the readjustment process.

Polychaetes and amphipods as commensals with pagurids from the Alaska shelf

Abstract Polychaetous annelids and/or amphipod crustaceans were associated with a total of 1715 (20.0 %) out of 8594 pagurids examined from the continental shelf of Alaska. Ten species of polychaetes (Eunoe depressa, E. nodosa, E. senta, Arctonoe vittata, Gattyana ciliata, Cheilonereis cyclurus, Eusyllis blomstrandi, Polydora commensalis, Lanassa venusta, and Crucigera zygophora) and at least three species of amphipods (Melita spp., Parapleustes pugettensis, and Podoceropsis nitida) were recorded with the following pagurids: Pagurus aleuticus, P. capillatus, P. confragosus, P. ochotensis, P. rathbuni, P. setosus, P. trigonocheirus, Elassochirus cavimanus, and Labidochirus splendescens. Eunoe depressa, Cheilonereis cyclurus, Polydora commensalis and Podoceropsis nitida have been previously reported with pagurids. A decrease in the frequency of occurrence of commensals with pagurids from the northeastern Gulf of Alaska to Norton Sound and an increase from the latter region to the southeastern Chukchi Sea wa...

The Macrobenthos of Sites within Prince William Sound, Alaska, Prior to the Exxon Valdez Oil Spill

Benthic fauna within three bays (Rocky and Zaikof Bays, and Port Etches) of outer Prince William Sound, Alaska are examined. The data represent the only detailed benthic faunal information available for the period prior to a major oil spill by the tanker Exxon Valdez within the Sound. The spatial distribution of fauna determined by classification and ordination resulted in eight station groups. Stepwise multiple discriminant analysis demonstrated a relationship between station groups, sediment grain size and nitrogen. Major faunal differences were observed within Rocky and Zaikof Bays between 1982 and 1990. The faunal differences between the two time periods demonstrate the extreme temporal variability that might be expected within Prince William Sound. The study serves as a cautionary note to avoid conclusions about the effects of disturbance to the benthos on a single data set. An explanation for temporal differences within the bays is presented.

Ptychodactis aleutiensis, a new species of ptychodactiarian sea anemone (Cnidaria: Anthozoa: Actiniaria) from the Aleutian Islands, Alaska

Abstract We describe a new species of ptychodactiarian sea anemone, Ptychodactis aleutiensis, and redefine the family Ptychodactiidae and the previously monotypic genus Ptychodactis to accommodate P. aleutiensis sp. nov. Individuals of the new species were photographed and collected at depths of less than 20 m off the Aleutian Islands, Alaska. Many were found detached, adrift in the water. The species differs from the only other member in its genus, Ptychodactis patula, in having more tentacles, tentacles only at the margin, frilled structures associated with only two siphonoglyphs, infertile primary mesenteries, oral stomata, holotrichous nematocysts of two size classes in the tentacles, actinopharynx, and mesenterial filaments, and by the morphology of the holotrichs and spirocysts. It is the fourth species of ptychodactiarian described; Ptychodactis is the only genus of suborder Ptychodacteae with more than one species.

Some aspects of the biology of the parasitic gastropod, Asterophila japonica Randall and Heath (Prosobranchia: Melanellidae), From Southeastern Chukchi Sea and Northeastern Bering Sea, Alaska

Abstract The endoparasitic gastropod, Asteropbila japonica, was found within two arctic sea stars, Leptasterias polaris aceruata and L. arctica. Aspects treated here include (1) parasite- host spatial distribution (2) parasite-host interactions and (3) parasite reproductive observations.