Robert P. Stone

Primnoa pacifica is the most ecologically important coral species in the North Pacific Ocean where it provides important habitat for commercially important fish and invertebrates. Ocean acidification (OA) is more rapidly increasing in high-latitude seas because anthropogenic CO ₂ uptake is greater in these regions. This is due to the solubility of CO ₂ in cold water and the reduced buffering capacity due to low alkalinity of colder waters. Primnoa pacifica colonies were cultured for six to nine months in either pH 7.55 (predicted 2100 pH levels) or pH 7.75 (control). Oocyte development and fecundity in females, and spermatocyst stages in males were measured to assess the effects of pH on gametogenesis. Oocyte diameters were 13.6% smaller and fecundities were 30.9% lower in the Year 2100 samples, indicating that OA may limit oocyte formation, potentially through lipid limitation. A higher proportion of vitellogenic oocytes (65%) were also reabsorbed (oosorption) in the Year 2100 treatment. Lowered pH appeared to advance the process of spermatogenesis with a higher percentage of later stage sperm compared to control controls. There was a laboratory effect observed in all measurement types, however these only significantly affected the analyses of spermatogenesis. These results indicate that reproduction may not be possible in an acidified ocean, or that if spawning could occur, spawned oocytes would not be sufficiently equipped to support the normal development of larvae.

The Wnt/β-catenin signaling pathway is known to play critical roles in a wide range of cellular processes: cell proliferation, differentiation, migration and embryonic development. Importantly, dysregulation of this pathway is tightly associated with pathogenesis in most human cancers. Therefore, the Wnt/β-catenin pathway has emerged as a promising target in anticancer drug screening programs. In the present study, we have isolated three previously unreported metabolites from an undescribed sponge, a species of Monanchora (Order Poecilosclerida, Family Crambidae), closely related to the northeastern Pacific species Monanchora pulchra, collected from deep waters off the Aleutian Islands of Alaska. Through an assortment of NMR, MS, ECD, computational chemical shifts calculation, and DP4, chemical structures of these metabolites have been characterized as spirocyclic ring-containing sesterterpenoid (1) and cholestane-type steroidal analogues (2 and 3). These compounds exhibited the inhibition of β-catenin response transcription (CRT) through the promotion of β-catenin degradation, which was in part implicated in the antiproliferative activity against two CRT-positive colon cancer cell lines.

Gorgonian octocorals are the most abundant corals in Alaska where they provide important structural habitat for managed species of demersal fish and invertebrates. Fifty-nine gorgonian species have been reported from Alaska waters but little is known about their life history characteristics to help us gauge their ability to recover from seafloor disturbance. Colonies of the holaxonian Calcigorgia spiculifera were tagged beginning in 1999 at three sites in Chatham Strait, Southeast Alaska, using scuba and their growth measured annually for up to 5 years. Colonies were video recorded, and computer image analysis tools provided calibration of video images for measuring the length of several branches. Growth data indicate that C. spiculifera grows much slower (6.0 mm yr^-1) than other gorgonians in Alaska for which there are data and that intraspecific growth is highly variable. We fit a Bayesian linear mixed-effects model that showed that average colony growth was significantly reduced with warmer temperature and presence of necrosis. The model further indicated that growth may slow among larger (older) colonies. Based on these results and previous studies, we propose that gorgonian growth rates are taxonomically constrained at the Suborder level and that holaxonians grow the slowest followed by scleraxonians and calcaxonians (2–3 times as fast). Findings of this study indicate that it would take approximately 60 years for C. spiculifera to grow to its maximum size and depending on the location and size of the parental standing stock, at least one and possibly 10 additional years for recruitment to occur. Our results further indicate that colonies that are injured, perhaps chronically in areas of frequent disturbance, grow at slower rates and if the current trend of ocean warming continues then we can expect these corals to grow more slowly, and the habitats they form will require more time to recover from disturbance.

Extensive new collections of latrunculid sponges from British Columbia, the Aleutian Islands, and the Gulf of Alaska, have extended the distributions of known species Latrunculia oparinae Samaai & Krasokhin, 2002, from the Russian Sea of Okhotsk, L. velera Lehnert et al., 2006, from the Aleutian Islands, and L. austini Samaai et al., 2006, from British Columbia. New material has facilitated detailed re-descriptions of these species and in situ images have improved our understanding of their living morphology and ecology. Several new species of Latrunculia were discovered within these collections: sympatric species Latrunculia hamanni sp. nov. and L. oparinae are described here and differentiated from each other by various field characteristics, and L. lincfreesei sp. nov. is described from the Gulf of Alaska. In terms of their higher systematics, L. austini and L. hamanni sp. nov. are recognisable within the subgenus Latrunculia du Bocage, 1869, and L. lincfreesei sp. nov. in subgenus Biannulata Samaai et al., 2006. A third subgenus, Uniannulata subgen. nov., is proposed for L. oparinae, L. velera and several fossil species in southern New Zealand and Western Australian Eocene fossiliferous sediments. In all of these species the subsidiary whorl, apical whorl, and apex of the anisodiscorhabd are fused. Living species of Uniannulata subgen. nov. are thus far restricted to the North Pacific Ocean. A new genus, Bomba gen. nov., is proposed for a rare latrunculid species, Bomba endeavourensis gen. et sp. nov., discovered in deep waters on British Columbia’s Endeavour Ridge. Finally, Latrunclava gen. nov. is proposed for species with long, sceptre-like anisoconicorhabds in addition to the typical, smaller anisodiscorhabds; Latrunclava imago gen. et sp. nov. is described from the central Aleutian Islands.

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.

Two new species of the genus Stelletta and one new species of Ancorina are described from the Aleutian Islands of Alaska and compared to congeners of the region. This is the first record of the genus Ancorina in the North Pacific Ocean. Stelletta ovalae Tanita 1965 is also reported for the first time from the Bering Sea and Alaska.