Brenda Konar

University of Alaska Fairbanks · College of Fisheries and Ocean Sciences

Barnacles are a foundation species in intertidal habitats. During the Pacific Marine Heatwave (PMH), intertidal barnacle cover increased in the northern Gulf of Alaska (GoA); however, the role of pelagic larval supply in this increase was unknown. Using long-term monitoring data on intertidal benthic (percent cover) and pelagic larval populations (...

Climate change is causing atmospheric warming, leading to increasing global temperatures. Warming is especially evident in high latitude regions, leading to losses in glacial mass and consequences downstream. Pacific Blue mussels are a vital species in such downstream coastal environments where they provide services such as stabilizing substrate, f...

Amphiboreal taxa are often composed of vicariant phylogroups and species complexes whose divergence and phylogeographic affinities reflect a shared history of chronic isolation and episodic trans-Arctic dispersal. Ecological filters and shifting selective pressures may also promote selective sweeps, niche shifts and ecological speciation during col...

Environmental changes associated with rapid climate change in the Arctic, such as the increased rates of sedimentation from climatic or anthropogenic sources, can enhance the impact of abiotic stressors on coastal ecosystems. High sedimentation rates can be detrimental to nearshore kelp abundance and distribution, possibly due to increased mortalit...

Species distribution models (SDMs) are used to map and predict the geographic distributions of animals based on environmental covariates. Typically, SDMs require high‐resolution habitat data and time series information on animal locations. For data‐limited regions, defined as having scarce habitat or animal survey data, modeling is more challenging...

Mass mortality events provide valuable insight into biological extremes and also ecological interactions more generally. The sea star wasting epidemic that began in 2013 catalyzed study of the microbiome, genetics, population dynamics, and community ecology of several high-profile species inhabiting the northeastern Pacific but exposed a dearth of...

The Pacific blue mussel ( Mytilus trossulus ) is a foundation species in high-latitude intertidal and estuarine systems that creates complex habitats, provides sediment stability, is food for top predators, and links the water column and the benthos. M. trossulus also makes an ideal model species to assess biological responses to environmental vari...

Kelps are a dominant macrophyte group and primary producer in Arctic nearshore waters that provide significant services to the coastal ecosystem. The quantification of these services in the Arctic is constrained, however, by limited estimates of kelp depth extent, which creates uncertainties in the area covered by kelp. Here, we test the environmen...

Seaweeds are foundation species across near-subtidal and intertidal zones, including when detached and free-floating and then cast ashore as wrack. Wrack is sometimes removed by humans for aesthetics or to be used as fertilizer. The study of wrack as an important habitat and resource for macroinvertebrates in high latitudes has been limited. To det...

Beach-cast wrack is an important resource that is commonly harvested by humans, and its removal can have consequences for coastal ecosystems. To further our understanding of wrack dynamics within high latitude ecosystems, our study objectives were to: 1) quantify spatio-temporal differences in beach-cast wrack biomass and composition, 2) quantify a...

Cycling of organic carbon in the ocean has the potential to mitigate or exacerbate global climate change, but major questions remain about the environmental controls on organic carbon flux in the coastal zone. Here, we used a field experiment distributed across 28° of latitude, and the entire range of 2 dominant kelp species in the northern hemisph...

Sea star wasting—marked in a variety of sea star species as varying degrees of skin lesions followed by disintegration— recently caused one of the largest marine die-offs ever recorded on the west coast of North America, killing billions of sea stars. Despite the important ramifications this mortality had for coastal benthic ecosystems, such as inc...

Mussels occupy a key middle trophic position in nearshore food webs linking primary producers to predators. Climate‐related environmental changes may synergistically combine with changes in predator abundance to affect intertidal ecosystems. We examined the influence of two major events on mussel (Mytilus trossulus) abundance in the northern Gulf o...

Estuarine habitats typically exhibit spatial and temporal variability due to fluctuating hydrological inputs and heterogenous coastal formations. In high-latitude regions, such as the Gulf of Alaska, shifts in coastal hydrology may be further exacerbated by climate warming leading to structural responses in nearshore estuarine fish communities. To...

The coastal zone of the Canadian Arctic represents 10% of the world’s coastline and is one of the most rapidly changing marine regions on the planet. To predict the consequences of these environmental changes, a better understanding of how environmental gradients shape coastal habitat structure in this area is required. We quantified the abundance...

Coastal ecosystems in Alaska are undergoing rapid change due to warming and glacier recession. We used a natural gradient of glacierized to non-glacierized watersheds (0–60% glacier coverage) in two regions along the Gulf of Alaska—Kachemak Bay and Lynn Canal—to evaluate relationships between local environmental conditions and estuarine fish commun...

Coastal ecosystems in high latitudes are increasingly impacted by glacial melt and river discharge due to climate change. One way to understand ecosystem responses to these stressors is assessing trophic relationships. The goal of this study was to better understand how hydrography influences trophic structure in high-latitude rocky intertidal syst...

Killer whales (Orcinus orca) are top predators throughout the world’s oceans. In the North Pacific, the species is divided into three ecotypes—resident (fish-eating), transient (mammal-eating), and offshore (largely shark-eating)—that are genetically and acoustically distinct and have unique roles in the marine ecosystem. In this study, we examined...

High-latitude coastal environments are experiencing dramatic changes due to climate warming, specifically enhanced glacier melt is modulating downstream environmental conditions in coastal watersheds and altering biological processes. Here, we examine rocky intertidal community structure, recruitment of key organisms, and environmental correlates a...

The coastal zone of the Canadian Arctic represents 10% of the world’s coastline and is one of the most rapidly changing marine regions on the planet. To predict the consequences of these environmental changes, a better understanding of how environmental gradients shape coastal habitat structure in this area is required. We quantified the abundance...

Sea otter (Enhydra lutris) populations in southwest Alaska declined substantially between about 1990 and the most recent set of surveys in 2015. Here we report changes in the distribution and abundance of sea otters, and covarying patterns in reproduction, mortality, body size and condition, diet and foraging behavior, food availability, health pro...

Some of the longest and most comprehensive marine ecosystem monitoring programs were established in the Gulf of Alaska following the environmental disaster of the Exxon Valdez oil spill over 30 years ago. These monitoring programs have been successful in assessing recovery from oil spill impacts, and their continuation decades later has now provide...

Marine heatwaves are global phenomena that can have major impacts on the structure and function of coastal ecosystems. By mid-2014, the Pacific Marine Heatwave (PMH) was evident in intertidal waters of the northern Gulf of Alaska and persisted for multiple years. While offshore marine ecosystems are known to respond to these warmer waters, the resp...

A primary goal in the study of producer-herbivore interactions is to characterize the tradeoffs between primary producer growth and defense. Across the Aleutian Island Archipelago, the widespread decline in sea otters has resulted in reduced predation on sea urchins, which has led to increases in urchin populations, the formation of urchin barrens,...

Trophic downgrading in coastal waters has occurred globally during recent decades. On temperate rocky reefs, this has resulted in widespread kelp deforestation and the formation of sea urchin barrens. We hypothesize that the intact kelp forest communities are more spatially variable than the downgraded urchin barren communities, and that these diff...

The changing global climate is having profound effects on coastal marine ecosystems around the world. Structure, functioning, and resilience, however, can vary geographically, depending on species composition, local oceanographic forcing, and other pressures from human activities and use. Understanding ecological responses to environmental change a...

Compelling new evidence shows that kelp production contributes an important and underappreciated flux of carbon in the ocean. Major questions remain, however, about the controls on the cycling of this organic carbon in the coastal zone, and their implications for future carbon sequestration. Here we used field experiments distributed across 28° lat...

In Alaska, interest in harvesting seaweeds for personal use is growing and information on potential impacts of this activity on sustainability of wild populations is lacking. This study provides information on reproductive timing and size, standing crop, and harvest rebound of three commonly harvested seaweeds in Southcentral Alaska: the rockweed,...

Trophic interactions can result in changes to the abundance and distribution of habitat-forming species that dramatically reduce ecosystem functioning. In the coastal zone of the Aleutian Archipelago, overgrazing by herbivorous sea urchins that began in the 1990s resulted in widespread deforestation of the region’s kelp forests, which led to lower...

Trophic interactions can result in changes to the abundance and distribution of habitat-forming species that dramatically reduce ecosystem health and functioning. Nowhere may this be as dramatic as in the coastal zone of the Aleutian Archipelago, where overgrazing by herbivorous sea urchins that began in the 1980s resulted in widespread deforestati...

Foundation species have strong, positive effects on local community structure; increasing biodiversity and species abundances by providing food and habitat. On coastal temperate and subpolar rocky reefs, canopy-forming kelps form three-dimensional habitats that support numerous fish, invertebrate, and algal species. Throughout the Aleutian Archipel...

Sea stars are ecologically important in rocky intertidal habitats where they can play an apex predator role, completely restructuring communities. The recent sea star die-off throughout the eastern Pacific, known as Sea Star Wasting Disease, has prompted a need to understand spatial and temporal patterns of sea star assemblages and the environmenta...

In coastal waters around the world, the dominant primary producers are benthic macrophytes, including seagrasses and macroalgae, that provide habitat structure and food for diverse and abundant biological communities and drive ecosystem processes. Seagrass meadows and macroalgal forests play key roles for coastal societies, contributing to fishery...

The continental shelf around the Aleutian Islands supports important commercial and subsistence fisheries as well as multiple seabird and marine mammal populations. To sustainably manage these populations, more information is needed on the distribution of the benthic communities that support some of the top level consumers. Given the vast size and...

The nearshore system, from benthic to upper trophic levels, was examined in Kachemak Bay, Alaska as part of the Gulf Watch Alaska Long-term monitoring program from 2012 to 2016. Important habitat types (rocky intertidal, seagrass beds, soft-sediment gravel beaches) and quantitative information on key biotic elements of these habitat types (macroalg...

Size, growth, and density have been studied for North American Pacific coast sea urchins Strongylocentrotus purpuratus, S. droebachiensis, S. polyacanthus, Mesocentrotus (Strongylocentrotus) franciscanus, Lytechinus pictus, Centrostephanus coronatus, and Arbacia stellata by various workers at diverse sites and for varying lengths of time from 1956...

In the Eastern Pacific (EP) the only region where rhodolith beds have been well studied in terms of taxonomy, ecology, distribution and conservation status is the Gulf of California. Outside this region the knowledge of rhodolith-forming species is attributed to the initial separate floristic surveys of Dawson and Lemoine, performed more than 50 ye...

Kelp forests and the many vital ecosystem services they provide are threatened as the severity of climate change and other anthropogenic stressors continues to mount. Particularly in the North Pacific, sea surface temperature is warming and glacial melt is decreasing salinity. This study explored the resiliency of early life-history stages of these...

Biogeographic breaks are often described as locations where a large number of species reach their geographic range limits. Samalga Pass, in the eastern Aleutian Archipelago, is a known biogeographic break for the spatial distribution of several species of offshore-pelagic communities, including numerous species of cold-water corals, zooplankton, fi...

Intertidal monitoring projects are often limited in their practicality because traditional methods such as visual surveys or removal of biota are often limited in the spatial extent for which data can be collected. Here, we used imagery from a small unmanned aerial vehicle (sUAV) to test their potential use in rocky intertidal and intertidal seagra...

Predictive tools and a large new dataset for the northeastern Chukchi Sea (NECS) are used here to help identify regional differences and potential future shifts in the magnitude of Hg biomagnification in the Arctic. At the base of the food web in the NECS, concentrations of total mercury (THg) in phytoplankton (20-µm mesh) ranged from 4–42 ng g⁻¹ d...

The snow crab Chionoecetes opilio and Arctic lyre crab Hyas coarctatus are prominent members of the Chukchi Sea epifaunal community. A better understanding of their life history will aid in determining their role in this ecosystem in light of the changing climate and resource development. In this study, the size frequency distribution, growth, and...

High-latitude kelp beds may be at risk from increasing sedimentation rates due to glacial melt. Nereocystis luetkeana (hereafter Nereocystis) sporophytes (canopy-forming) occur infrequently downstream of glacial melt where thick layers of sediment accumulate, while Saccharina latissima (hereafter Saccharina) sporophytes (understorey) are common in...

Sea otters Enhydra lutris and sea stars both excavate clams and leave behind foraging pits. If the source of pits can be determined with confidence, they may provide information about benthic foragers without direct foraging observations. Our objectives were to determine (1) if pits can be attributed to either predator (sea otters or sea stars) usi...

Significance Kelp forests support diverse and productive ecological communities throughout temperate and arctic regions worldwide, providing numerous ecosystem services to humans. Literature suggests that kelp forests are increasingly threatened by a variety of human impacts, including climate change, overfishing, and direct harvest. We provide the...

Rocky intertidal communities are structured by local environmental drivers, which can be dynamic, fluctuating on various temporal scales, or static and not greatly varying across years. We examined the role of six static drivers (distance to freshwater, tidewater glacial presence, wave exposure, fetch, beach slope, and substrate composition) on int...

The abundant snow crab Chionoecetes opilio, and the fairly abundant Arctic lyre crab Hyas coarctatus are part of the extensive epifaunal community in the Chukchi Sea, Alaska. Gaining a better understanding of the distribution and growth of both species, which is impacted by mesoscale environmental gradients, will be important in the light of climat...

The abundant snow crab Chionoecetes opilio, and the fairly abundant Arctic lyre crab Hyas coarctatus are part of the extensive epifaunal community in the Chukchi Sea, Alaska. Gaining a better understanding of the distribution and growth of both species, which is impacted by mesoscale environmental gradients, will be important in the light of climat...

Fish distributions can be influenced by changes in their local habitat features and regional oceanographic conditions, both of which can occur at different spatial scales. Currently, the coastal waters throughout the Aleutian Archipelago are dominated by two discrete habitats types, kelp forests and urchins barrens, both of which span known U.S. bi...

Arctic marine epibenthos contribute significantly to the regional biomass, remineralization and redistribution of organic carbon, and are key elements of local food webs. The main purpose of this study was to describe the epibenthic invertebrate community on the Alaska Beaufort Shelf and identify links between community patterns and environmental d...

The northern Bering and Chukchi seas are areas in the Pacific Arctic characterized by high northward advection of Pacific Ocean water, with seasonal variability in sea ice cover, water mass characteristics, and benthic processes. In this review, we evaluate the biological and environmental factors that support communities of benthic prey on the con...

Records of high resolution climate variability in the past are essential to understanding the climate change observed today. This is particularly true for Arctic regions, which are rapidly warming. Prior to instrumental data, proxy records can be extracted from high-latitude climate archives to provide critical records of past Arctic climate variab...

Sea otters (Enhydra lutris) inhabiting the Aleutian Islands have stabilized at low abundance levels following a decline and currently exhibit restricted habitat-utilization patterns. Possible explanations for restricted habitat use by sea otters can be classified into two fundamentally different processes, bottom-up and top-down forcing. Bottom-up...

Sea otters, Enhydra lutris (Linnaeus, 1758), forage in a mosaic of habitat types. The relative use of heterogeneous environments by sea otters is largely unknown. Here, we examined whether foraging sea otters selectively use habitats based on substratum grain size and/or prey availability. Use by foraging sea otters was determined by the occurrence...

In the Aleutian Archipelago, two distinct organizational states of kelp forest communities exist, foliose algal assemblages and deforested barren areas. The canopy-forming kelp Eualaria fistulosa can be found in both states, although it is much less abundant in the deforested state. In contrast, sea urchins also occur in both states, but they are c...

Epibenthic communities play a key role in ecosystem functioning in Arctic shelf Seas, such as in the Chukchi Sea in the Pacific Arctic. These communities, however, are patchily distributed and are influenced by various environmental parameters. Along with taxonomic composition, another community aspect that may vary spatially and be influenced by t...

This study used benthic surveys and manipulative experiments to examine (1) if boundaries between kelp forests and urchin barrens exist at multiple locations spanning the Aleutian Archipelago, (2) if these boundaries are spatially stable, and (3) how changes in algal density within the kelp forests influence the ability of urchins to invade them. O...

Kelp forests are patchy fish-associated habitats, which can vary greatly in their size, foundation species, and several physical habitat attributes. The structure of fish assemblages can vary with these characteristics and with the location of the assemblage within the forest, i.e. edges versus interiors. This study quantified the biological and ph...

Gastropod assemblages from nearshore rocky habitats were studied over large spatial scales to (1) describe broad-scale patterns in assemblage composition, including patterns by feeding modes, (2) identify latitudinal pattern of biodiversity, i.e., richness and abundance of gastropods and/or regional hotspots, and (3) identify potential environmenta...

High-arctic boulder communities that are impacted by anthropogenic and natural influences can result in the removal or scouring of sessile organisms leaving either open space or damaged organisms. This project asks how sessile communities recover after disturbances by determining (1) timing of recolonization, (2) grazer effects on recolonization, a...

Field courses using scuba allow university students to experience kelp forests and other shallow, subtidal ecosystems. They are unusually effective for instilling essential scientific values: an appreciation of natural history and an enhanced ability to ask meaningful questions and think holistically. After teaching such courses at six institutions...

We combine data collected from the past 40 years to estimate the indirect effects of sea otters (Enhydra lutris) on ecosystem carbon (C) production and storage across their North American range, from Vancouver Island to the western edge of Alaska's Aleutian Islands. We find that sea otters, by suppressing sea urchin (Strongylocentrotus spp) populat...

The Aleutian Archipelago coastal ecosystem has undergone a dramatic change in community composition during the past two decades. Following the removal of ∼99% of the sea otters, Enhydra lutris, from the ecosystem, changes to the benthic communities resulted in widespread losses to most of the region’s kelp beds and corresponding increases in the pr...

The establishment of algal spores plays an essential role in adult kelp distribution and abundance patterns. Sedimen-tation is a key variable regulating algal spore settlement and success, possibly controlling species-specific dominance in situ. Laboratory experiments were used to determine spore attachment and survival rates of two Alaskan canopy-...

Macroalgal and urchin barren communities are alternately stable and persist in the Aleutians due to sea otter presence and absence. In the early 1990s a rapid otter population decline released urchins from predation and caused a shift to the urchin-dominated state. Despite increases in urchin abundance, otter numbers continued to decline. Although...

Relationships of diversity, distribution and abundance of benthic decapods in intertidal and shallow subtidal waters to 10 m depth are explored based on data obtained using a standardized protocol of globally-distributed samples. Results indicate that decapod species richness overall is low within the nearshore, typically ranging from one to six ta...