Ken G Ryan

Ken G Ryan
Victoria University of Wellington · School of Biological Sciences

PhD

About

270
Publications
18,531
Reads
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3,667
Citations
Citations since 2017
24 Research Items
1327 Citations
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250
Additional affiliations
June 2002 - present
Victoria University of Wellington
Position
  • Professor (Associate)
January 1991 - June 2002
Callaghan Innovation
Position
  • Researcher

Publications

Publications (270)
Article
Full-text available
Sea ice is a key habitat in the high latitude Southern Ocean and is predicted to change in its extent, thickness and duration in coming decades. The sea-ice cover is instrumental in mediating ocean–atmosphere exchanges and provides an important substrate for organisms from microbes and algae to predators. Antarctic krill, Euphausia superba, is reli...
Conference Paper
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Dinoflagellates are among the most ecologically diverse group of microalgae. Dinoflagellate species from the family Symbiodiniaceae form endosymbiotic associations with invertebrates, such as corals, sea anemones, and jellyfish. Strains of dinoflagellates are maintained alive in culture collections worldwide. This is labor-intensive, expensive, and...
Article
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Symbiodiniaceae are a diverse group of dinoflagellates, the majority of which are free-living and/or associated with a variety of protists and other invertebrate hosts. Maintenance of isolated cultures is labour-intensive and expensive, and cryopreservation provides an excellent avenue for their long-term storage. We aimed to cryopreserve 15 cultur...
Article
Full-text available
Dinoflagellates are among the most diverse group of microalgae. Many dinoflagellate species have been isolated and cultured, and these are used for scientific, industrial, pharmaceutical, and agricultural applications. Maintaining cultures is time-consuming, expensive, and there is a risk of contamination or genetic drift. Cryopreservation offers a...
Article
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Ice-associated microalgae make a significant seasonal contribution to primary production and biogeochemical cycling in polar regions. However, the distribution of algal cells is driven by strong physicochemical gradients which lead to a degree of microspatial variability in the microbial biomass that is significant, but difficult to quantify. We ad...
Article
Leucothoids (family Leucothoidae Dana, 1852) are amphipods often associated with sponges and are relatively poorly recorded in New Zealand waters, with only four species previously recorded. Two newly discovered species, Leucothoe agripeta sp. nov. and L. tumultus sp. nov. are described from a sponge off Aotea Quay, Wellington, New Zealand and an a...
Article
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Sea ice supports a unique assemblage of microorganisms that underpin Antarctic coastal food-webs, but reduced ice thickness coupled with increased snow cover will modify energy flow and could lead to photodamage in ice-associated microalgae. In this study, microsensors were used to examine the influence of rapid shifts in irradiance on extracellula...
Article
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Understanding community assembly is a key goal in community ecology. Environmental filtering influences community assembly by excluding ill‐adapted species, resulting in communities with similar functional traits. An RLQ (a four‐way ordination) analysis incorporating spatial data was run on a dataset of 642 species of cheilostomes (Bryozoa) from 77...
Article
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• This review summarises knowledge on the ecology, toxin production, and impacts of toxic freshwater benthic cyanobacterial proliferations. It documents monitoring, management, and sampling strategies, and explores mitigation options. • Toxic proliferations of freshwater benthic cyanobacteria (taxa that grow attached to substrates) occur in streams...
Article
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Benthic cyanobacterial proliferations in rivers are have been reported with increasing frequency worldwide. In the Eel and Russian rivers of California, more than a dozen dog deaths have been attributed to cyanotoxin toxicosis since 2000. Periphyton proliferations in these rivers comprise multiple cyanobacterial taxa capable of cyanotoxin productio...
Article
Toxic benthic cyanobacterial proliferations may pose a significant risk in freshwater ecosystems. In New Zealand, the only anatoxin-producing benthic species reported to date is Microcoleus autumnalis. Management of M. autumnalis proliferations has primarily focussed on mitigating the health risks associated with human and canine contact with the c...
Preprint
Full-text available
Benthic cyanobacterial proliferations in rivers are have been reported with increasing frequency worldwide. In the Eel and Russian rivers of California, more than a dozen dog deaths have been attributed to cyanotoxin toxicosis since 2000. Periphyton proliferations in these rivers comprise multiple cyanobacterial taxa capable of cyanotoxin productio...
Article
Full-text available
Background The hadal zone encompasses the deepest parts of the world’s ocean trenches from depths of ∼6,000–11,000 m. The communities observed at these depths are dominated by scavenging amphipods that rapidly intercept and consume carrion as it falls to the deepest parts of the trenches. New samples collected in the Tonga Trench provide an opportu...
Article
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Modularity is a fundamental concept in biology. Most taxa within the colonial invertebrate phylum Bryozoa have achieved division of labour through the development of specialized modules (polymorphs), and this group is perhaps the most outstanding exemplar of the phenomenon. We provide a comprehensive description of the diversity, morphology and fun...
Article
Historical sea ice core chlorophyll-a (Chla) data are used to describe the seasonal, regional, and vertical distribution of ice algal biomass in Antarctic landfast sea ice. The analyses are based on the Antarctic Fast Ice Algae Chlorophyll-a data set, a compilation of currently available sea ice Chla data from landfast sea ice cores collected at ci...
Article
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Groundwater is a major source of New Zealand's water supply and supports baseflows in rivers. Microbial communities in groundwater ecosystems mediate biogeochemical processes, and it is therefore crucial to understand microbial diversity in these ecosystems. We analysed bacterial assemblages from 35 New Zealand groundwater monitoring sites with var...
Article
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This study measured the nutritional composition of foods consumed by the northern yellow-cheeked crested gibbon (Nomascus annamensis) in northeastern Cambodia. One group of N. annamensis was studied, and focal animal sampling was used to observe their feeding behavior. The study was conducted for 4 months (January-April 2015) in the dry season and...
Article
Full-text available
Microorganisms confined to annual sea ice in the Southern Ocean are exposed to highly variable oxygen and carbonate chemistry dynamics because of the seasonal increase in biomass and limited exchange with the underlying water column. For sea-ice algae, physiological stress is likely to be exacerbated when the ice melts; however, variation in carbon...
Article
Proteorhodopsin (PR) is a wide-spread protein found in many marine prokaryotes. PR allows for the potential conversion of solar energy to ATP, possibly assisting in cellular growth and survival during periods of high environmental stress. PR utilises either blue or green light through a single amino acid substitution. We incubated the PR-bearing ba...
Article
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Environmental stressors impact marine larval growth rates, quality and sizes. Larvae of the Antarctic bivalve, Laternula elliptica, were raised to the D-larvae stage under temperature and pH conditions representing ambient and end of century projections (-1.6°C to +0.4°C and pH 7.98 to 7.65). Previous observations using light microscopy suggested p...
Article
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Annual fast ice at Scott Base (Antarctica) in late summer contained a high biomass surface community of mixed phytoflagellates, dominated by the dinoflagellate, Polarella glacialis. At this time of the year, ice temperatures rise close to melting point and salinities drop to less than 20. At the same time, pH levels can rise above 9 and nutrients c...
Article
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Elevated temperatures associated with ocean warming and acidification can influence development and, ultimately, success of larval molluscs. The effect of projected oceanic changes on fertilisation and larval development in an Antarctic bivalve, Laternula elliptica, was investigated through successive larval stages at ambient temperature and pH con...
Article
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Benthic cyanobacterial blooms are increasing worldwide and can be harmful to human and animal health if they contain toxin-producing species. Microbial interactions are important in the formation of benthic biofilms and can lead to increased dominance and/or toxin production of one or few taxa. This study investigated how microbial interactions con...
Conference Paper
New Zealand flowers are often characterised as drab with simple colour patterns. We wanted to know if this is also the case in colour palettes more characteristic of pollinators. Although humans have trichromatic colour vision, our colour palette is different from the vision of many pollinators. Hymenoptera have a trichromatic uv-blue-green colour...
Article
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Antarctic fast ice provides a habitat for diverse microbial communities, the biomass of which is mostly dominated by diatoms capable of growing to high standing stocks, particularly at the ice−water interface. While it is known that ice algae exude organic carbon in ecologically significant quantities, the mechanisms behind its distribution and com...
Article
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Antarctic sea ice provides a stable environment for the colonisation of diverse and highly specialised microbes that play a central role in the assimilation and regulation of energy through the Antarctic food web. However, little is known about how the bacterial community composition changes within the sea ice, the functional role bacteria play in...
Article
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Groundwater plays an important role in New Zealand water supplies and hence monitoring activities are conducted regularly. Most monitoring programmes aim to evaluate groundwater chemistry and almost completely overlook the microbial component in this ecosystem. In our present study, the bacterial community structure of groundwater in the Wairarapa...
Article
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Ocean acidification substantially alters ocean carbon chemistry and hence pH but the effects on sea ice formation and the CO2 concentration in the enclosed brine channels are unknown. Microbial communities inhabiting sea ice ecosystems currently contribute 10-50% of the annual primary production of polar seas, supporting overwintering zooplankton s...
Data
Ocean acidification substantially alters ocean carbon chemistry and hence pH but the effects on sea ice formation and the CO2 concentration in the enclosed brine channels are unknown. Microbial communities inhabiting sea ice ecosystems currently contribute 10-50% of the annual primary production of polar seas, supporting overwintering zooplankton s...
Article
Global demand for freshwater has led to unprecedented levels of water abstraction from riverine systems. This has resulted in large alterations in natural river flows. The deleterious impacts of reduced flows on fish and macroinvertebrate abundances have been thoroughly investigated; in contrast, there is a limited understanding of the potential fo...
Article
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Neurotoxic pesticides, such as neonicotinoids, negatively affect the cognitive capacity and fitness of non-target species, and could also modify interspecific interactions. We tested whether sublethal contamination with neonicotinoid could affect foraging, colony fitness and the outcome of behavioural interactions between a native (Monomorium antar...
Article
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Groundwater is a vital component of rural and urban water supplies in New Zealand. Although extensive monitoring of chemical and physical properties is conducted due to the high demand for this valuable resource, current information on its bacterial content is limited. However, bacteria provide an immense contribution to drive the biogeochemical pr...
Article
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Primary production in coastal Antarctica is primarily contributed from three sources: sea ice algae, phytoplankton, and microphytobenthos. Compared to other eastern Antarctic sites, the sea ice microalgal biomass at Casey Station, in spring 2005 was relatively low, 3.84 ± 1.67 to 21.6 ± 13.3 mg chl-a m−2 but productive, 103–163 mg C m−2 day−1. The...
Article
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Bacteria that utilize sunlight to supplement metabolic activity are now being described in a range of ecosystems. While it is likely that phototrophy provides an important competitive advantage, the contribution that these microorganisms make to the bioenergetics of polar marine ecosystems is unknown. In this minireview, we discuss recent advances...
Article
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Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoanatoxin-a. However, little is known about the co-occurrence of anatoxin-producing and non-anatoxin-producing strains within mats. There is also no data on variation in anatoxin content among toxic genotypes isolated from the same mat. In this study, 30 Ph...
Article
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Cyanobacteria play an important role in the primary productivity of many ecosystems and are dominant in non-marine polar environments. Apart from detecting low levels of cyanobacteria-like pigments in the Southern Ocean, little effort has been spent in trying to elucidate Cyanobacteria in Antarctic sea ice. Here, we report the first use of culture,...
Article
The physiological response to increased temperature during dark exposure was examined in phytoplankton and sea ice algae that had overwintered in McMurdo Sound, Antarctica and Tromsø Sound, Norway. Under ice phytoplankton and sea ice algae from McMurdo Sound were incubated in the dark for 22 days and 23 days respectively at − 2, 4 and 10 °C, while...
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Article
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Sea ice microalgae actively contribute to the pool of dissolved organic matter (DOM) available for bacterial metabolism, but this link has historically relied on bulk correlations between chlorophyll a (a surrogate for algal biomass) and bacterial abundance. We incubated microbes from both the bottom (congelation layer) and surface brine region of...