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Gocke, C, Janussen D, Reiswig HM, Jarrell SC, Dayton PK.  2015.  Rossella podagrosa Kirkpatrick, 1907: A valid species after all. Zootaxa. 4021:169-177. AbstractWebsite

In this study we provide evidence that the species Rossella podagrosa Kirkpatrick, 1907, commonly considered a synonym of Rossella racovitzae Topsent, 1901, is truly a valid species. We show that it can be clearly distinguished from other species especially when taking into consideration the in situ habitus of the sponge in combination with the spicules. Furthermore we demonstrate the weaknesses in the so far published synonymy concept for the very complicated genus Rossella Carter, 1872. From this we conclude that the best strategy for further analysis of Rossella and establishment of acceptable synonymies will need to be based on detailed examination of the spicules, the holotypes, and in situ habitus. When possible it will be useful to analyze specimens from all Antarctic oceanographic regions.

Dayton, PK, Robilliard GA, Devries AL.  1969.  Anchor ice formation in McMurdo Sound, Antarctica, and its biological effects. Science. 163:273-274.   10.1126/science.163.3864.273   AbstractWebsite

Aggregations of ice platelets accumulate below the annual sea ice (subice platelet layer) and on the bottom (anchor ice) to depths of 33 metres. Observations of ice platelets adhering to submerged lines support the conclusions that 33 metres is teh lower limit for ice formation in the water column in this area. The rising anchor ice lifts epibenthic fauna and has a pronounced effect on the distribution of the epibenthic organisms.

Dayton, PK, Oliver JS.  1977.  Antarctic soft-bottom benthos in oligotrophic and eutrophic environments. Science. 197:55-58.   10.1126/science.197.4298.55   AbstractWebsite

The benthos of the east and west sides of McMurdo Sound, Antarctica, is characterized by dramatically different infaunal assemblages. The eutrophic East Sound has higher infaunal densities than almost any other benthic assemblage in the world. In contrast, the oligotrophic West Sound, bathed by currents from beneath the Ross Ice Shelf, has patterns of mobile epifauna and low infauna density similar to bathyl deep-sea communities.

Dayton, PK.  1982.  Antarctica, coastal ecology. The Encyclopedia of Beaches and Coastal Environments. ( Schwartz ML, Ed.).:4-43.: Hutchinson Ross Publishing Company Abstract
Kinlan, BP, Graham MH, Sala E, Dayton PK.  2003.  Arrested development of giant kelp (Macrocystis pyrifera, Phaeophyceae) embryonic sporophytes: A mechanism for delayed recruitment in perennial kelps? Journal of Phycology. 39:47-57.   10.1046/j.1529-8817.2003.02087.x   AbstractWebsite

Delayed recruitment of microscopic stages in response to cyclical cues is critical to the population dynamics of many annual and seasonally reproducing perennial seaweeds. Microscopic stages may play a similar role in continuously reproducing perennials in which adult sporophytes are subject to episodic mortality, if they can respond directly to the unpredictable onset and relaxation of unfavorable conditions. We experimentally evaluated the potential for temporary reduction in limiting resources (light, nutrients) to directly delay recruitment of giant kelp (Macrocystis pyrifera (L.) C.A. Agardh) gametophytes and embryonic sporophytes. Laboratory cultures were subjected to limiting conditions of light and nutrients for 1 month and then exposed to nonlimiting conditions for 10 days. Gametophytes in all treatments failed to recruit to sporophytes after 2 weeks, suggesting they are not a source of delayed recruitment in giant kelp. Sporophytes in light-limited treatments, however, survived and grew significantly slower than non-light-limited controls. When stimulated with light, light-limited sporophytes grew from 2 to>10 times faster than unstimulated controls depending on nutrient availability. These results suggest that limiting resources can delay recruitment of embryonic giant kelp sporophytes for at least 1 month. Flexible timing of recruitment from embryonic sporophytes may enhance persistence of continuously reproducing perennial species when mac- roscopic adults are subject to episodic large-scale removals.

Dayton, PK, Oliver JS, Thrush SF, Hammerstrom K.  2019.  Bacteria defend carrion from scavengers. Antarctic Science. 31:13-15.   10.1017/s0954102018000457   AbstractWebsite

Carrion in the form of dead seal pups and algal mats placed on soft bottom habitats at Explorers Cove and Salmon Bay, McMurdo Sound, attract scavenging invertebrates that are driven away by hydrogen sulphide produced by sulphate-reducing bacteria sequestered below a layer of Beggiatoa/Thioploca-like filamentous bacteria. This system is usually found for lipid-rich marine mammal carrion, but also occurred with natural algal mats.

Dayton, PK.  1975.  Benthic communities of McMurdo Sound. Antarctic Journal of the United States. 10:136-137. AbstractWebsite
Oliver, JS, Watson DJ, O'Connor EF, Dayton PK.  1976.  Benthic communities of McMurdo Sound. Antarctic Journal of the United States. 11:58-59. AbstractWebsite
Dayton, PK, Robillia.Ga.  1971.  Benthic Community near McMurdo Station. Antarctic Journal of the United States. 6:54-&. AbstractWebsite
Dayton, PK, Paine RT, Robilliard GA.  1970.  Benthic faunal zonation as a result of anchor ice at McMurdo Sound, Antarctica. Antarctic Ecology. 1( Holdgate M, Ed.).:244-258., London: Academic Press Abstract
Dayton, PK, Kooyman GL, Barry JP.  1984.  Benthic life under thick ice. Antarctic Journal of the United States. 19:128-128. AbstractWebsite
Dayton, PK, Jarrell SC, Kim S, Parnell PE, Thrush SF, Hammerstrom K, Leichter JJ.  2019.  Benthic responses to an Antarctic regime shift: food particle size and recruitment biology. Ecological Applications. 29   10.1002/eap.1823   AbstractWebsite

Polar ecosystems are bellwether indicators of climate change and offer insights into ecological resilience. In this study, we describe contrasting responses to an apparent regime shift of two very different benthic communities in McMurdo Sound, Antarctica. We compared species-specific patterns of benthic invertebrate abundance and size between the west (low productivity) and east (higher productivity) sides of McMurdo Sound across multiple decades (1960s-2010) to depths of 60 m. We present possible factors associated with the observed changes. A massive and unprecedented shift in sponge recruitment and growth on artificial substrata observed between the 1980s and 2010 contrasts with lack of dramatic sponge settlement and growth on natural substrata, emphasizing poorly understood sponge recruitment biology. We present observations of changes in populations of sponges, bryozoans, bivalves, and deposit-feeding invertebrates in the natural communities on both sides of the sound. Scientific data for Antarctic benthic ecosystems are scant, but we gather multiple lines of evidence to examine possible processes in regional-scale oceanography during the eight years in which the sea ice did not clear out of the southern portion of McMurdo Sound. We suggest that large icebergs blocked currents and advected plankton, allowed thicker multi-year ice, and reduced light to the benthos. This, in addition to a possible increase in iron released from rapidly melting glaciers, fundamentally shifted the quantity and quality of primary production in McMurdo Sound. A hypothesized shift from large to small food particles is consistent with increased recruitment and growth of sponges on artificial substrata, filter-feeding polychaetes, and some bryozoans, as well as reduced populations of bivalves and crinoids that favor large particles, and echinoderms Sterechinus neumayeri and Odontaster validus that predominantly feed on benthic diatoms and large phytoplankton mats that drape the seafloor after spring blooms. This response of different guilds of filter feeders to a hypothesized shift from large to small phytoplankton points to the enormous need for and potential value of holistic monitoring programs, particularly in pristine ecosystems, that could yield both fundamental ecological insights and knowledge that can be applied to critical conservation concerns as climate change continues.

Dayton, PK, Robillia.Ga, Paine RT, Dayton LB.  1974.  Biological accommodation in the benthic community at McMurdo Sound, Antarctica. Ecological Monographs. 44:105-128.   10.2307/1942321   AbstractWebsite
Dunton, KH, Dayton PK.  1995.  The biology of high latitude kelp. ( Skjoldal H, Hopkins C, Erikstad KE, Leinaas HP, Eds.).:499-507., Tromsø, Norway: Elsevier Abstract
Dayton, PK, Tegner MJ.  1990.  Bottoms beneath troubled waters: benthic impacts of the 1982-1984 El Nino in the temperate zone. Global ecological consequences of the 1982-83 El Nino-Southern Oscillation. ( Glynn PW, Ed.).:433-472., Amsterdam ; New York: Elsevier Abstract
Thrush, S, Dayton P, Cattaneo-Vietti R, Chiantore M, Cummings V, Andrew N, Hawes I, Kim S, Kvitek R, Schwarz AM.  2006.  Broad-scale factors influencing the biodiversity of coastal benthic communities of the Ross Sea. Deep-Sea Research Part Ii-Topical Studies in Oceanography. 53:959-971.   10.1016/j.dsr2.2006.02.006   AbstractWebsite

Early ecological research in McMurdo Sound revealed local spatial gradients in community structure associated with variations in anchor ice disturbance, fast ice and snow cover, and the effects of predators. Research contrasting the cast and west sides of McMurdo Sound has shown major differences in benthic communities, which have been attributed to oceanographic influences on the advection of water-column productivity and the frequency of fast ice break-out. Despite these regional and local differences, coastal benthic communities in McMurdo Sound show a high level of stability, and contain a variety of large and potentially very long-lived species. In Terra Nova Bay, about half way along the Victoria Land Coast of the western Ross Sea, the coastal benthic communities provide some insightful contrasts with those in McMurdo Sound. For example, the abundance and depth distribution of dominant species such as Sterechinus neumayeri and Adamussium colbecki are markedly different from McMurdo Sound. In both locations communities dominated by large sponges are most prolific in regions that are free from iceberg disturbance of the seabed. A recent assessment of northern Victoria Land coastal benthic communities, in conjunction with multibeam imagery of the seafloor, further highlights the importance of iceberg disturbance in structuring Antarctic benthic communities. A comparative synthesis of these coastal ecological studies enables us to generate hypotheses concerning the relative importance of different environmental drivers in structuring benthic communities. Overlain on the regular latitudinal shifts in physical factors such as light regime, are regional fluctuations that are controlled by atmospheric and oceanographic circulation patterns and coastal topography/bathymetry. Change in diversity along the western coast of the Ross Sea is predicted to be influenced by three main factors (1) ice disturbance (e.g., via anchor ice and advection of supercooled water or icebergs), (2) photosynthetically available radiation (affected by ice and snow cover and water clarity), (3) the locations of polynyas and advection of planktonic production and larvae. Interactions between these factors are expected to result in non-linear changes along the latitudinal gradient. While predictions generated from these hypotheses remain to be rigorously tested, they provide indications of how benthic communities may respond to changes in production, disturbance and the stability of coastal sea ice. (c) 2006 Elsevier Ltd. All rights reserved.

Dayton, PK, Tegner MJ.  1984.  Catastrophic storms, El Nino, and patch stability in a southern California kelp community. Science. 224:283-285.   10.1126/science.224.4646.283   AbstractWebsite


Moore, SE, DeMaster DP, Dayton PK.  2000.  Cetacean habitat selection in the Alaskan Arctic during summer and autumn. Arctic. 53:432-447. AbstractWebsite

Ten years (1982-91) of sighting data from aerial surveys offshore of northern Alaska were analyzed to investigate seasonal variability in cetacean habitat selection. Distinct habitats were described for bowhead whales (Balaena mysticetus), white whales (Delphinapterus leucas), and gray whales (Eschrichtius robustus) on the basis of habitat selection ratios calculated for bathymetric and ice cover regimes. In summer, bowheads selected continental slope waters and moderate ice conditions; white whales selected slope and basin waters and moderate to heavy ice conditions; and gray whales selected coastal/shoal waters and open water. In autumn, bowheads selected inner shelf waters and light ice conditions; white whales selected outer shelf and slope waters and moderate to heavy ice; and gray whales selected coastal and shoal/trough habitats in light ice and open water. Habitat differences among species were significant in both seasons (ANOVA F > 28, p < 0.00001). Interseasonal depth and ice cover habitats were significantly different for bowhead whales (p < 0.00002), but not for gray whales p > 0.35). White whale depth habitat was significantly different between seasons (p < 0.00002), but ice cover habitat was not (p < 0.08).

Dayton, PK.  1994.  Community landscape: scale and stability in hard bottom marine communities. Aquatic ecology : scale, pattern, and process. ( Giller PS, Hildrew AG, Raffaelli DG, Eds.).:289-332., Oxford ; Boston: Blackwell Scientific Publications Abstract
Denley, EJ, Dayton PK.  1985.  Competition among macroalgae. Handbook of Phycological Methods. ( Littler MM, Lettler DS, Eds.).:511-530.: Cambridge University Press Abstract
Genin, A, Dayton PK, Lonsdale PF, Spiess FN.  1986.  Corals on seamount peaks provide evidence of current acceleration over deep-sea topography. Nature. 322:59-61.   10.1038/322059a0   AbstractWebsite

Geological and physical studies of seamounts have suggested the existence of distinct deep-sea habitats, characterized by exposed rocky bottom and a unique current regime1–9. However, few biological data have been collected for deep seamounts10–12. Here we present some of the first quantitative observations of hard-bottom (non-hydrothermal) fauna in the deep sea. These observations show that black corals (antipatharians) and horny corals (gorgonians) present on the slopes of a multi-peaked seamount are more abundant near peaks, compared with mid-slope sites at corresponding depths. On narrow peaks corals are most abundant on the crest, whereas on wide peaks, coral densities are highest at the edge of the crest. The abundance of corals also increases on knobs and pinnacles. Physical models and observations2,4–9,13–15, together with our direct measurements, suggest that the seamount topography affects the local current regime. Corals appear to benefit from flow acceleration, and some of their patterns of distribution can be explained by current conditions. These results suggest that suspension feeders have some potential as indicators of prevailing currents at deep hard-bottom sites.

Dayton, PK.  1986.  Cumulative impacts in the marine realm. Cumulative environmental effects: a binational perspective. ( Beanlands GE, Ed.).:79-84., Ottawa, Ont.Washington, D.C.: Canadian Environmental Assessment Research Council ;U.S. National Research Council Abstract
Barry, JP, Dayton PK.  1988.  Current patterns in Mcmurdo Sound, Antarctica and their relationship to local biotic communities. Polar Biology. 8:367-376.   10.1007/bf00442028   AbstractWebsite

Current speed and direction measurements collected during summer (January–February) and sping (November–December) of 1984 indicated that currents in McMurdo Sound, Antarctica were dominated by oscillatory flow associated with diurnal tidal components (O1, K1, P1). Net flow was southward in the eastern Sound, mixed in the central Sound, and northward in the western Sound. Short term observations (<5 days) from nearshore stations indicated a similar but more sluggish pattern of tidal and mean flow. Hydrographic data collected during the same period indicated a similar pattern of cold water with low chlorophyll a content flowing northward from under the Ross Ice Shelf in the western Sound and denser, slightly warmer water with higher chlorophyll a content flowing southward in the eastern Sound. Previous studies have shown that productivity is higher in the eastern Sound than in the west, apparently due to the circulation pattern. The western Sound consists of waters from beneath the Ross Ice Shelf which have a lower phytoplankton standing stock than eastern Sound waters which enter from the north. More sluggish current speeds in the western Sound result in even lower particle fluxes past benthic consumers. Finally, more persistent ice cover in the west further inhibits in situ primary productivity.