Nearshore subtidal community structure compared between inner coast and outer coast sites in Southeast Alaska

Abstract

Processes that structure subarctic marine communities, particularly in glaciated regions, are not well understood. This understanding is needed as a baseline and to manage these communities in the face of future climatedriven changes. This study investigates two coastal regions of Southeast Alaska with the goals to (a) identify and compare patterns of subtidal community structure for macroalgal, fish, macroinvertebrate ([5 cm), and small epibenthic invertebrate (\5 cm) communities between inner coast and outer coast sites and (b) link patterns of community structure to habitat and environmental parameters. Species assemblage and benthic habitat data were used to compare species diversity and community composition at 6 m and 12 m depths at nine inner coast and nine outer coast sites. Multivariate analysis was applied to reduce environmental variables to major gradients, to resolve community structure, and to relate community structure to habitat and environmental variables. Increased salinity and decreased temperature at outer coast sites compared with inner coast sites were associated with community structure, with greater species diversity at outer coast sites at 6 m depth. Invertebrate community composition was associated with benthic habitat, including crust and coralline algae for macroinvertebrates, and algal cover and substrate for small epibenthic invertebrates. This research suggests that marine communities in glaciated regions are strongly influenced by freshwater input and that future climate-driven changes in freshwater input will likely result in marine community composition changes.

The influence of depth and substrate inclination on sessile assemblages in subantarctic rocky reefs (Magellan region)

“…In general, communities inhabiting these environments are strongly influenced by biotic factors such as predation, intense competition for space (Witman and Cooper 1983;Sebens 1985) and grazing (Sebens 1985). Moreover, physical factors including water depth, light intensity, water flow, surface inclination, sedimentation, oxygen, water temperature and salinity play an important role structuring the benthic communities inhabiting rocky walls (Hiscock 1985;Leichter and Witman 1997;Miller and Etter 2008;Laudien and Orchard 2012;Pirtle et al 2012). Among these factors, depth is probably one of the most studied (Logan et al 1984;Ojeda and Santelices 1984;Ojeda and Dearborn 1989; Barnes and Brockington 2003;Sahade et al 2004;Smale 2008;Konar Electronic supplementary material The online version of this article (doi:10.1007/s00300-015-1729-5) contains supplementary material, which is available to authorized users.…”

Ceriantharia (Cnidaria) of the World: an annotated catalogue and key to species

“… Pachycerianthus fimbriatus McMurrich, 1910: 35–38; Carlgren 1912a : 44–47; Arai 1971 : 1677–1680; Arai 1972 : 311–317; Arai and Walder 1973 : 1086–1088, 1090; Arai and Karakashian 1973 : 719–720, 723–724; Tiffon and Hugon 1977 : 289–290; Uchida 1979 : 188; Carter 1995 : 6; Fautin 1998 : 135; Arai 1985 : 47–48; Pirtle et al 2012 : 1896, 1905–1906; Stampar et al 2014b : 350, 352 …”

“…http://zoobank.org/A1F21314-9AFC-42C8-A5DE-1A70BB00D3AE (?) Cerianthus elongatus Kwietniewski, 1898: 426-427;Pax 1910: 167 Pachycerianthus fimbriatus McMurrich, 1910Carlgren 1912a: 44-47;Arai 1971Arai : 1677Arai -1680Arai 1972: 311-317;Arai and Walder 1973: 1086-1088, 1090Arai and Karakashian 1973: 719-720, 723-724;Tiffon and Hugon 1977: 289-290;Uchida 1979: 188;Carter 1995: 6;Fautin 1998: 135;Arai 1985: 47-48;Pirtle et al 2012Pirtle et al : 1896Pirtle et al , 1905Pirtle et al -1906Stampar et al 2014b: 350, 352 Pachycerianthus plicatus Carlgren, 1924den Hartog 1997: 352;Arai 1971Arai : 16771680 (? ) Pachycerianthus torreyi Arai, 1965: 205-210;Arai 1971Arai : 16771680 Type locality.…”

Effects of elevated temperature and sedimentation on grazing rates of the green sea urchin: implications for kelp forests exposed to increased sedimentation with climate change

“…Changes in macroalgal composition and abundance are likely to occur simultaneously with grazing pressure in response to increase sediment. In Alaska, kelp diversity is typically lower near points of glacial sediment input and the sediment-tolerant S. latissima is often the dominant kelp species [21,46,47]. Although extreme increases in sedimentation can result in loss of even this sedimenttolerant kelp, as in Norway where sediment deposition from frequent flooding resulted in the loss of 90% of S. latissima forests along the southern coast [48].…”