Abstract Booklet

2021 Kachemak Bay Science Conference

Access all information about the conference at kachemakbayscience.org See daily agenda for Links to Pre-recorded Talks Abstract: Since 2006 Kachemak Bay National Estuarine Research Reserve (KBNERR) has been monitoring for harmful algal blooms in Kachemak Bay. Harmful algal blooms (HABs) occur when groups of algae produce toxins causing severe health effects and potential fatalities. The main goal of KBNERR’s Harmful Algal Bloom Monitoring Program is to look for groups of phytoplankton that are known to produce toxins that can result in shellfish poisoning for humans and marine mammals. Phytoplankton samples are collected by trained community monitors at numerous locations throughout Kachemak Bay. These volunteers are trained in identification and sampling techniques, providing a valuable service to the community. Samples are processed and analyzed by KBNERR. Weekly reports on phytoplankton are distributed from KBNERR to state managers, private and public organizations, oyster farmers, local harvesters, tribal organizations, and our community monitors. Monitoring phytoplankton also provides us with valuable baseline information on the phytoplankton bloom cycles in Kachemak Bay.

Notes______Abstract: Paralytic shellfish toxins(PSTs) have become an increasingly severe and pervasive problem in Alaska. There is currently no state-operated biotoxin monitoring program for non-commercial shellfish in Alaska, yet rural communities rely on native shellfish for subsistence. The Chugach Regional Resources Commission(CRRC) is a Tribal consortium representing seven coastal Tribes in the Prince William Sound and Lower Cook Inlet regions of Alaska. CRRC operates the Alutiiq Pride Marine Institute(APMI), located in Seward. CRRC/APMI presently conducts ocean monitoring across its Tribal region through its Chugach Region Ocean Monitoring(CROM) program. The current CROM program works with Tribal members in each community to conduct bi-weekly ocean sampling. These samples are sent to APMI along with field data for analysis. At present, this program provides comprehensive water chemistry/ocean acidification data for all participating Tribal regions. This project will expand CRRC’s existing CROM program to include monitoring for harmful phytoplankton species, as well as shellfish toxins. Phytoplankton abundance data will be collected via phytoplankton tows. Tribal technicians will be trained in basic algal speciation techniques to provide preliminary field data. Final phytoplankton samples will be sent to APMI for molecular species detection using quantitative Polymerase Chain Reaction(qPCR). Similarly, shellfish samples will also be collected and sent to APMI, where biotoxin testing will be conducted using an Enzyme-Linked Immunosorbent Assay(ELISA). Regular reports will be disseminated to both Tribal members and the general public via the CRRC/APMI websites and social media outlets. Final data from the CROM program will be utilized to provide a comprehensive view of baseline oceanic conditions across the coastal Gulf of Alaska. This project will build regional Tribal capacity through CRRC/APMI to monitor and study the precipitating factors and incidences of PSTs in native shellfish in order to support safe and sustainable harvest opportunities for both local communities and the shellfish industry in southcentral Alaska.

Notes______Abstract: Harmful algal blooms (HABs) are a growing but unpredictable risk to many stakeholders and communities in Alaska. Subsistence shellfish harvesting, commercial aquaculture operations, and wildlife are all potentially impacted by the toxins produced when population numbers of certain phytoplankton species explode locally. Many researchers, environmental coordinators, community members, regulators and organizations in Alaska are working to better understand the factors that lead to HAB events in different regions throughout Alaska, including Kachemak Bay. The Alaska Harmful Algal Bloom (AHAB) network provides a statewide approach to the awareness, research, monitoring and response to HABs with the goal of reducing the risk to humans and wildlife. By reviewing recent HAB events in and around Alaska, we discuss the current state of knowledge, ongoing research and monitoring activities, and how future collaboration and coordination throughout the state can help us better understand, predict and respond to HABs. And while a perfectly predictive model of where HABs will appear may be unattainable, our continued collective efforts will help minimize the risks and mitigate the impacts of HABs in Alaska.

Notes______Abstract: Phytoplankton are important primary producers in Alaska’s coastal waters and their community composition is shaped by both environmental conditions and predation. Glaciers are receding rapidly worldwide due to climate change and this trend is particularly apparent in many of Alaska’s coastal fjords. Glacially influenced watersheds contribute high concentrations of sediment and alter the chemistry of marine ecosystems. It is unknown how these differences affect phytoplankton community composition and abundance. To address this question, water samples for this project were collected monthly from six sites across Kachemak Bay as part of Alaska EPSCoR Fire and Ice Project, from June through September of 2020. Five of these sites are considered estuarine, and have freshwater input with varying amounts of glaciation, creating a gradient of hydrological conditions. The water samples were collected at 5 meters deep, filtered for DNA and nutrients, and whole water samples were preserved for flow cytometry and microscopy. Cell counts from flow cytometry and microscopy were used to compare phytoplankton community composition and abundance across the glacial gradient. We determined that percent glaciation was not significantly correlated with diversity of phytoplankton in estuarine areas. However, a late season bloom of picoplankton dominated glacial estuaries, but was absent in non-glacial estuaries. These differences suggest that as glaciers recede phytoplankton community composition and bloom timing may shift.

Notes______Abstract: In Alaska paralytic shellfish poisoning (PSP) is caused by ingestion of seafood products containing saxitoxins, potent neurotoxins produced by the dinoflagellate Alexandrium catenella. PSP is usually caused by consumption of toxin-containing bivalves (mussels, clams, etc.), but there is growing evidence that toxins can also be transferred to other biota during Alexandrium blooms, including species that do not feed directly on shellfish. Here, we report preliminary results from two concurrent projects examining the potential occurrence of PSP toxins in marine fish and invertebrates across southcentral and southwest Alaska. Samples were collected at a variety of sites in Lower Cook Inlet, Prince William Sound, the Kodiak Islands, the Alaska Peninsula, the Aleutians and the Pribilof Islands, and were analyzed for PSP toxin concentrations by ELISA and HPLC. Resulting data indicate toxin concentrations in forage fishes (saxitoxin equivalents, STX Eq.) reached the highest levels in Dolly Varden (208 µg/100g), Pacific Herring (428 µg/100g) and Pacific Sand Lance (758 µg µg/100g). Toxins were also present in the organs of predatory fishes, with maximum concentrations in the kidney (170 µg/100g), liver (103 µg/100g) and digestive organs (49 µg/100g). In contrast toxin levels in muscle tissue and roe were very low (≤13 and ≤8 µg/100g, respectively). Among invertebrates tested, the highest toxin concentrations were recorded in crabs (1,650 µg/100g), sea stars (672 µg/100g) and predatory snails (483 µg/100g), but with notable levels in detritivorous amphipods (171 µg/100g), urchins (99 µg/100g), octopus (71 µg/100g) and tunicates (63 µg/100g). Regional and interspecific differences in toxin levels among fish and invertebrates were examined, along with implications for high level marine predators and the Alaskan seafood. Notes______Abstract: The Common Murre (Uria aalge) is a colonially nesting seabird whose breeding success can be influenced by predation pressure and prey availability. Following the North Pacific Marine Heatwave and unprecedented die-off in 2015-2016, we resumed annual monitoring of Common Murres at Gull Island in Kachemak Bay, AK, for comparison with baseline data from the late-1990s. After observing complete reproductive failures on productivity plots from 2016-2018 (mean±SD: 0.00 ±0 chicks/pair), in 2019 Common Murres fledged chicks for the first time since the heatwave (0.26 chicks/pair), but at roughly half the rate from 1995-1999 (0.54 ±0.15 chicks/pair). To quantify predator disturbance as a potential factor influencing breeding success from 2016 to 2019, we used time lapse cameras to monitor the frequency and intensity of predator induced flushes and rates of direct and facilitated predation over the course of the breeding season. Predator disturbance was observed in all years, but flushes were more frequent and prolonged in 2016-2018 than in 2019. Rates of direct predation on adults by Bald Eagles (Haliaeetus leucocephalus) and direct and facilitated predation on eggs by Glaucous-winged (Larus glaucescens) and Herring Gulls (Larus argentatus) were also higher in 2016-2018 compared with 2019. Associated information on forage fish indicated that high quality prey were more available in the system during 2019 than previous years, which may have contributed to greater synchrony in laying, facilitating resilience to predator disturbance. These results, in addition to continued monitoring of breeding success in the context of predator disturbance and prey availability, will help to understand Common Murre recovery following the die-off.

Notes______Abstract: The Alaska Maritime National Wildlife Refuge (part of the U.S. Fish and Wildlife Service) annually monitors seabird reproductive success and population trend at East Amatuli Island, in lower Cook Inlet’s Barren Islands. In 2021 the COVID-19 pandemic cancelled the annual seabird monitoring field-camp there. However, nine cameras photographed cliff and burrow habitat every 90 minutes through the nesting season. Originally initiated to overcome terrain challenges of in-person observation at this location, automated imaging of nesting seabirds provided additional advantage during the pandemic. From the camera images we determine murre and kittiwake nest attendance; laying, hatching, and fledging dates; and chick counts. For tufted puffins, periodic counts from images of birds near their burrows are being used as indices of puffin population trend and possibly reproductive effort and output; development of these methods continues. Long pursued as a method of seabird monitoring, time-lapse camera technology has only recently become reliable enough to be used as a standard monitoring method in remote locations.

Notes______Abstract: During 2016-2017, we sampled gulls for antimicrobial resistant bacteria and fitted birds with satellite tracking devices at sites on the Kenai Peninsula and throughout Alaska to determine if gulls acquire antimicrobial resistant bacteria from human inputs and to assess transport of bacteria through their movements. On the Kenai Peninsula, we sampled gull feces at the Soldotna landfill, mouth of the Kasilof River, mouth of the Kenai River, and upper Kenai River during summer and found evidence that gulls likely acquire antimicrobial resistant bacteria from areas receiving human inputs, such as effluent or solid waste. Movement patterns of gulls and information on the prevalence of antimicrobial resistant bacteria suggest that gulls may disperse bacteria among sites on the Kenai Peninsula through local movements. We also collected gull fecal samples from Adak, Anchorage, Bethel, Cold Bay, Nome, and Utqiagvik, revealing that gulls acquire clinically important antimicrobial resistant bacteria from human inputs at areas throughout Alaska, which may also be dispersed at broad spatial scales via migratory movements. Critically important antimicrobial resistance was found in bacteria harbored by gulls on the Kenai Peninsula and in Anchorage. This was the first report of carbapenem resistant bacteria in wildlife in North America, though genomic characterization of these bacteria did not support direct transmission between gulls and hospital patients. Through ongoing research, we aim to further elucidate environmental pathways through which wildlife acquire clinically important antimicrobial resistant bacteria and how these pathways relate to the health of humans, animals, and the environment. Our findings may inform management activities and outreach initiatives aiming to mitigate the spread of antimicrobial resistance from humans to gulls and minimize exposure of humans and pets to potentially harmful bacteria harbored by birds.

Notes______Abstract:

To document changes in forage fish and seabirds in lower Cook Inlet, Alaska, following the 2014 – 2016 North Pacific marine heatwave, we repeated historical (1995 – 1999) marine bird and acoustic-trawl surveys around two colonies (Gull and Chisik islands) during 2016 – 2019, and monitored population status and breeding success of Black-legged Kittiwakes (Rissa tridactyla, “kittiwakes”) and Common Murres (Uria aalge, “murres”) at colonies through 2020. Acoustic backscatter was dominated by juvenile pollock in 2016 and 2017, which reflects strong year classes in those years. Lowest overall prey densities were observed in 2018, which coincided with the lowest densities of birds at sea. Larger more nutritious sand lance and mature capelin were more available in 2019 than in previous years. At the colonies, large declines (>70%) in kittiwake and murre populations were observed on Chisik, and smaller declines were observed in kittiwakes (up to 26%) and murres (up to 46%) at Gull. Kittiwakes and murres had complete, or nearly complete, reproductive failure at Chisik from 2016 – 2019. At Gull Island, kittiwakes had complete (or nearly complete) failure in 2016 and 2018 but record high productivity in 2017 and 2019; whereas, murres produced chicks for the first time since the heatwave in 2019. In 2020, both species had reproductive success at Chisik for the first time since the heatwave. Murres at Gull also produced chicks in 2020; however, kittiwakes failed, contributing to a 5-year pattern of alternating reproductive failure and success since 2016. Seabird population declines, reproductive failures, and signals of malnutrition following the heatwave were coincident with low availability of high-quality prey in their foraging habitat, high levels of predator disturbance at colonies, and occasionally with harmful algal blooms. Continued monitoring of seabirds and forage fish in Cook Inlet will aid in understanding the ecosystem response to marine heatwaves in the future.

Notes______Abstract: In recent years, an interdisciplinary team of scientists and stakeholders has studied landscape-scale connectivity between slope and riparian wetlands and salmon-bearing headwater streams in south-central Alaska, with recent breakthroughs underscoring the central role played by groundwater. Groundwater provides half of of summer streamflow and modulates year-round stream temperatures, providing cold-water refugia in summer and warm-water refugia in winter. Most groundwater first discharges to and interacts with slope and riparian wetlands prior to discharging to streams. Groundwater that passes through nitrogen-fixing alder patches on hillslopes emerges with increased nitrogen concentrations. Nitrogen-enriched groundwater is thereafter delivered to riparian wetlands and streams. Above-ground biomass is higher in riparian wetlands that receive this nitrogen-rich groundwater than in riparian wetlands that do not receive this nitrogen-rich groundwater. Following the addition of nitrogen fertilizer, above-ground biomass is the same in both. Biomass from riparian wetlands is then deposited in streams, where isotopic evidence indicates it serves as the primary food source for stream invertebrates that feed juvenile salmonids. Nitrogen concentrations in streams are positively correlated with percent cover alder in the watershed. This is then reflected in stream processes, with leaf litter decomposition rates positively correlated with nitrogen concentrations and in-stream nitrogen-fixation rates negatively correlated with nitrogen concentrations. These findings have heightened stakeholder awareness of the tight linkages between limited groundwater resources, slope and riparian wetlands, and headwater streams, empowering community conversations that have resulted in demonstrable changes to policies and practices throughout the stakeholder community.

Notes______Abstract: Groundwater is an essential, yet limited resource. Across the globe, including the Kenai Lowlands, Alaska, a great percentage of the water that is used for public, commercial, industrial, and agriculture purposes is groundwater. However, groundwater is not only used by people, it is also used by groundwater-dependent ecosystems, including many wetlands, streams, and estuaries. In the Kenai Lowlands, groundwater discharge from seeps and springs plays a fundamental role in supporting streamflow, modulating stream temperatures, and delivering nitrogen subsidies from hillslopes to streamside wetlands and streams. These processes are critical for maintenance of stream habitat for salmonids. As population continues to grow, the consumptive use of groundwater also continues to grow, further stressing this limited but shared resource. Lacking a shared understanding, information, and tools to facilitate communication, continued groundwater depletion could lead towards economic, ecological, and cultural collapse. Therefore, stability and resilience of communities, like the Kenai Lowlands, depend on well-informed, science-based, collaborative decision-making. In this study, we seek to identify areas where groundwater resources, including aquifers and the seeps and springs they support, are most vulnerable to anthropogenic impacts using GIS-based Multi Criteria Decision Analysis (MDCA) framework. MCDA is a methodology for appraising alternatives on individual criteria and combining them into one overall assessment which can then be used to compare different plausible outcomes and aid management decisions. The results of this study will be information including visualizations identifying areas with higher degrees of groundwater vulnerability to anthropogenic impacts under specific conditions. These products can then be used to motivate meaningful discussions and decision-making regarding resource management in this region and showcase the use of groundwater vulnerability modeling and collaborative approaches to other communities facing competition for groundwater so they, too, may consider this approach. Notes______Abstract: Since 1997, Kenai Watershed Forum (KWF) has led efforts in education, restoration, and research on watersheds and water quality in the Kenai Peninsula. From its inception, water quality monitoring and conservation in local rivers and lakes has been central to KWF’s mission. KWF is currently engaged in a variety of water quality monitoring efforts with local partners, several of which we will highlight here. First, the Kenai River Baseline Water Quality Monitoring program is a biannual event that relies on nearly a dozen community partners to collect water samples throughout the Kenai River watershed. The effort has generated what is among the longest-running and most thorough water quality datasets in Alaska, and has been instrumental in identifying and finding solutions for issues such as two-stroke boat motor pollution. Second, since 2010 KWF has worked with the Alaska Department of Environmental Conservation to monitor bacteria concentrations in the lower Kenai River during the height of the personal use dipnet fishery. Data indicates fecal matter from gulls attracted to fish carcasses are the primary source of elevated bacteria concentrations, and revealed the need for mitigation actions such as beach raking. Finally, KWF is currently working with several agency partners to monitor water quality and quantity in the Vogel Lake area North of Nikiski, where an invasive pike population was identified in 2019. KWF will work with the Alaska Department of Fish and Game and Fish and Wildlife Service through Fall 2022 to generate a detailed map with information essential for a potential rotenone application to eliminate the pike infestation. As KWF approaches its 25th anniversary, finding solutions to local water quality issues remains at the heart of our mission.

Notes______Abstract: Peat depth is poorly catalogued in the Kenai Lowlands. These peatlands make up a large part of our landscape and provide important habitat for numerous species (USGS), contribute greatly to salmon stream function (Callahan et al. 2015; Robbins et al. 2017), and store vast amounts of organic carbon (IUCN). The Kachemak Bay National Estuarine Research Reserve has begun preliminary studies into peat depth variation across peatland type in order to better understand the carbon storing potential of our local peatlands. Sampling strategies were focused on soil probing across predetermined, gridded peatlands to probe refusal. Depths were recorded at each point, brought into a GIS, and interpolated depth surfaces were created for each sampled peatland. Average depth across all peatlands sampled exceeded the recorded organic soil depths present in the NRCS Soil Survey for the area putting them more in line with the estimated average boreal peat depth of 1.5-2.3 meters (Hugelius et al. 2020; Holmquist et al. 2014). This early effort will help inform the viability of bringing a carbon project to the Kenai Peninsula centered on peat carbon. Additionally, lessons learned from initial sampling will help inform local volunteer efforts to better catalogue peat depth across the Kenai Lowlands.

Notes______Abstract: Homer Drawdown, a local climate solutions community initiative organized by Kachemak Bay Conservation Society and Cook Inletkeeper, is pursuing the mission of uplifting the critical, yet undervalued carbon storing function of local peatlands. Using the book Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming, edited by Paul Hawken, we identified meaningful and well researched solutions that don’t just stabilize levels of greenhouse gasses in the atmosphere, but that actually draw emissions back down to sustainable levels. The Drawdown series is centered in the belief that community led, middle-out solutions, are the most influential solutions we can enact. After nine months of brainstorming and researching local solutions, the Homer Drawdown community democratically chose one achievable solution to put our collective energy towards over the next year: Community Education, Conservation and Restoration of Peatlands. Intact and functioning peatlands are not widely recognized as a resource commodity worth protecting, though they provide many direct benefits to the humans, ecosystems and aquifers of the Kenai Lowlands. Peatlands store vast amounts of carbon that has been sequestered over millennia. The retention of carbon in peatlands is a major benefit in mitigating the acceleration of global warming. Homer Drawdown recognizes that landscape change and land-use management issues are crucial to the reversal of rapid climate warming. The Kenai Lowlands support large areas of peatlands that are significant in the global carbon cycle. Homer Drawdown: Peatland Project aims to uplift the power of our local peatlands as an influential component of climate trajectories. The multi-pronged method that Homer Drawdown will use to achieve this goal includes a citizen science surveying initiative to put peatlands on the map, experimental restoration techniques, and direct education and communication with local policy makers, landowners and the larger community.

Notes______Abstract: The wet organic soils of peatland ecosystems are capable of storing immense amounts of carbon. They can also emit greenhouse gases through chemical processes that are initiated when the landscape is drained, burned, or otherwise degraded. The Kenai Peninsula’s high concentration of undisturbed carbon-storing peatlands is an ideal location for the Kachemak Bay National Estuarine Research Reserve’s (KBNERR) current work, evaluating the viability of a regional carbon project. Presented here, is a case study on the North Fork watershed of the Anchor River on the Kenai Peninsula of Alaska, focusing on one of the many steps necessary for evaluating a carbon project's potential: assessing the impacts to peatlands. The aim of this study is to gain a fuller understanding of the drivers of those impacts, by analyzing local land-uses and their subsequent effects on peatlands, measuring the rate of change occurring on the landscape, and gauging the potential amount of carbon that could be lost if that rate were to continue or increase. This case study's methods involve 1) finding a rate of change using historical aerial imagery and landcover data, 2) calculating the area where peatlands and development overlap using GIS map analysis, and 3) estimating carbon content of the peatlands and potential carbon emissions using existing soil depth datasets. The results of this case study identify a method for assessing impacts to peatlands that can be applied to larger landscapes for future conscientious land management, as well as provide a critical step in furthering the development of this carbon project.

Notes______Abstract: The Kenai Peninsula Cooperative Weed Management Area (CWMA) has been actively and effectively managing non-native plant species since 2003. It has been viewed by similar groups from around the state as the example for what a highly functioning CWMA in Alaska is capable of. As of December 2020, the group has officially changed to a Cooperative Invasive Species Management Area (CISMA). This is part of a nation-wide trend to include all taxa, both plant and animal, within these management areas in order to effectively combat the spread of all invasive species. This expansion in the breadth of this group will help to streamline outreach to the public, prevent new infestations from taking hold, and augment eradication efforts of the highest non-native threats on the Kenai Peninsula. As we transition to a CISMA, we will continue to be guided by multiple Strategic Plans, regularly developed work plans, and the partnerships that have long made this group effective at controlling the spread of invasive species on the Kenai Peninsula.

Notes______Abstract: The Kenai Peninsula Fish Habitat Partnership (KP-FHP) has cited invasive species as one of the largest threats to ecosystem health on the Kenai Peninsula. In the KP-FHPs 2011 Conservation Action Plan (CAP), four out of the seven Freshwater Targets were determined to be threatened by injurious aquatic invasive species; three of them being highly threatened. In this CAP, the KP-FHP notes Northern Pike, Elodea, and Reed Canarygrass as injurious aquatic invasive species currently infesting KP waters. As this was true in 2011, so is it today. While these populations persist in varying degrees on the Kenai Peninsula, land managers and partnering organizations have continued to strategize, prioritize, and implement eradication efforts in waterbodies and streams to protect our most highly vulnerable waters from the threats posed by these invaders. We will discuss these tactics in the context of the Freshwater Targets outlined in the KP-FHP 2011 CAP which will include an update on the state of freshwater aquatic invasive species on the Kenai Peninsula.

Notes______Abstract: Kenai Watershed Forum is a nonprofit organization based in Soldotna, Alaska leading several community-based conservation and education efforts. We will highlight two programs here, Stream Watch and Adopt-a-Stream. In 2011, KWF began administering a watershed education and stewardship volunteer program in partnership with the US Forest Service called Stream Watch. Since 2011, Stream Watch volunteers spent 14,000 hours providing peer-to-peer ecological education to 35,000 members of the public, removing 30,000 pounds of litter and debris from fish habitat, and protecting two miles of riverbank habitat at the most-visited sportfishing sites in Alaska. Themed in stewardship and education, KWF also manages the nationally-recognized Adopt-a-Stream environmental education program. Through Adopt-a-Stream, KWF has delivered natural resource education to a broad audience of children and adults since 2006. Using a hands-on and engaging model, Adopt-A-Stream aims to support the connection between healthy watersheds, the salmonid life cycle, and ecosystem conservation which benefit both water quality and local fish and wildlife habitat. K-12 students on the Kenai Peninsula adopt a nearby stream site to monitor and protect, leading to significant environmental investigations, curiosity, and active environmental stewardship. Together, Stream Watch and Adopt-a-Stream are examples of how to develop and engage responsible community stewardship of shared ecological resources.

Notes______Abstract: As carbon dioxide (CO2) concentrations in our atmosphere continue to rise, the oceanic uptake of CO2 is expected to further reduce seawater pH by 0.3-0.4 units by the year 2100, a process termed ocean acidification (OA). Anthropogenic changes in seawater chemistry have resulted in maladaptive behavioral and physiological responses in many marine organisms. While organism-level effects of OA are well recognized, the consequences for ecological species interactions are less understood. In addition to OA, ocean warming (OW) is concomitantly occurring, and sea surface temperature is expected to increase by 4C by the year 2100. Considering the oceans will both acidify and warm concurrently, multi-stressor manipulative experimentation is an emergent area of study that aims to examine the individual and interactive effects of these factors on marine organisms. I examined both the individual and interactive effects of an acidifying and warming ocean on the predator-prey relationship between a key sea star predator, Evasterias troschelii, and its gastropod prey, Lottia scutum. My thesis aims to characterize the individual and interactive effects of OA and OW on 1) the anti-predator behavior of L. scutum when exposed to their sea star predator, 2) the metabolic rate and thermal tolerance of L. scutum, 3) cortisol levels in L. scutum when exposed to their sea star predator, and 4) the role of the neurotransmitter GABA in modulating the behavior of L. scutum when exposed to their sea star predator. Preliminary results demonstrate that after acclimation, OW significantly decreased the critical thermal maximum (CTmax) of L. scutum, while OA did not. This underscores the need for factorial experimental designs in multi-stressor experimentation, as including multiple environmental parameters yields results that are ecologically relevant.

Notes______Abstract: Sea stars are keystone species in rocky intertidal habitats, structuring communities through their predation on primary space holders such as mussels. Amid the recent Pacific Marine Heatwave, an outbreak of sea star wasting syndrome (SSWS) led to dramatic declines in sea star abundance throughout the northern Gulf of Alaska. We investigated 1) how mussel abundance changed since the onset of SSWS, and 2) which sea star species and temperature metrics best explain variation in mussel abundance. Star abundance, mussel percent cover, density of large mussels, and density of mussels of all sizes were estimated approximately annually at Katmai National Park (KATM), Kachemak Bay (KBAY), Kenai Fjords National Park (KEFJ) and western Prince William Sound (WPWS). At KATM, KBAY, and KEFJ star abundance declined 40-100% after SSWS. Mussel cover increased above the long-term mean 1-3 years after declines in star abundance at KATM, KBAY, and KEFJ, but not at WPWS. Large mussel abundance increased to 65% above the long-term mean at KATM after SSWS. Large mussel abundance increased slightly at KBAY but did not increase at KEFJ or WPWS. Mussel abundance including all sizes did not differ before and after the onset of SSWS implying that recruitment didn’t change. Pisaster ochraceus and Pycnopodia helianthoides abundance and winter and spring temperatures together explained 22.4% of variation in mussels. The Pacific Marine Heatwave and SSWS outbreak may have interacted synergistically, with declines in macroalgae due to warm temperatures, increased available space, and relaxing top-down pressure on mussels. Shifts in intertidal community structure not only affect biodiversity in these regions, but changes to available prey are likely felt throughout the nearshore food web. For higher trophic level species, such as sea otters and sea ducks, this may culminate in a change in abundance and/or performance of these predators in the nearshore.

Notes______Abstract: Kachemak Bay beaches are changing in sometimes startling ways, and people are taking notice. This project highlights how the Center for Alaskan Coastal Studies developed a community-based monitoring project that creates an impactful learning opportunity for local youth and community members, and (b) allows for the collection of robust data about local sea star populations and the prevalence of sea star wasting syndrome (SSWS). In 2014, we used MARINe protocols to establish three permanent plot locations near the Peterson Bay Field Station to monitor for SSWS. Each season, we count and document signs of SSWS in all Evasterias troschelii (true stars), Pisaster ochraceus (ochre stars), Pycnopodia helianthoides (sunflower stars), Dermasterias imbricata (leather stars), and other local stars at these locatiosn. Through this, we documented a rapid increase in SSWS prevalence in late summer and early fall 2016, followed closely by a dramatic collapse of Evasterias and Pycnopodia populations. Survey data also reveal spatial and temporal variability for population recovery across the three sites. We also highlight examples of how SSWS survey activities have been integrated into K12 and college curriculum. Results from participant surveys and reflective writing demonstrated that involvement in this community-based monitoring project can affect sense of efficacy, curiosity, and stewardship. Data collected through these efforts have contributed to deeper understanding of SSWS at a local, national, and even international effort. Community monitoring projects like this can help to address questions about SSWS and nearshore ecology in the future, and there are implications for other regions and other changes in nearshore ecosystems. This project provides an example of a practical approach to climate change education and action that supports young people and community members in work that is interesting to them, builds scientific understanding within their community, and contributes data that are useful and usable by researchers. Notes______Abstract: Glacial recession caused by a warming climate is impacting the coastal ecosystem across the Gulf of Alaska. The Alaska EPSCoR Fire and Ice Program is a five-year project funded by the National Science Foundation to investigate the changes caused by increased freshwater and material fluxes from the land to the ocean. Research is taking place in two regions, Kachemak Bay and Lynn Canal (near Juneau). Researchers are using remote sensing, field data, lab experiments, modeling, and coastal resource user surveys to address three goals. First, we are characterizing the hydrological and biogeochemical dynamics of rivers across watersheds with varying glacial cover and the linkages to coastal oceanography. Second, we are quantifying biological responses of nearshore marine organisms to varying physical and chemical conditions across the watershed regions. Finally, we are increasing our understanding of how coastal resource users and managers may respond to anticipated future shifts in nearshore marine resources under a changing climate, and explore strategies for building adaptive capacity. Here, we share a video highlighting our research.

Notes______Abstract: Estuarine habitats are among the most productive ecosystems on earth and are supported by organic matter (OM) from both terrestrial and marine origins. In high-latitude systems, glaciers provide an additional source of highly bioavailable OM, originating from ancient detritus, microbial exudates, and petrogenic materials. Globally, glaciers export nearly 0.75 Mt of carbon to the ocean with roughly 13% of the annual flux produced by mass loss. Concurrent with climate change, a 25 to 35% reduction of total glacier volume is expected by the end of the century. As a result of these changes, the quantity and quality of OM exported to nearshore environments may be altered, potentially subjecting nearshore marine consumers to lower grade food sources, thus impacting ecosystem production. To assess the contribution of terrestrial OM to nearshore systems we performed bulk stable isotope analysis on particulate organic matter (POM) collected at select locations proximate to the river outflows of watersheds of varying glacial influence. There were pronounced seasonal patterns in POM δ13C (‰), roughly following a linear gradient with glaciation during peak glacial discharge in summer. However, despite these rough trends, no direct relationships were found between stream and nearshore water biogeochemical markers. Instead, POM δ13C (‰) was moderately negatively correlated r(33) = -0.40, p = 0.017 with heterotrophic bacteria abundance. These data suggest intermediate processes between glacial exports and POM, where bacteria and plankton are stimulated by terrestrial OM and nutrients and, in turn, influence the POM composition.

Notes______Abstract: Pacific blue mussels (Mytilus trossulus) are an integral part of the nutrient cycle in near-shore and estuarine ecosystems. As abundant filter feeders, mussels connect the water column and the benthos and serve as food to many higher trophic level species. High latitude estuaries receive freshwater runoff from both rivers and glaciers but can also be under oceanic influence. These hydrographic conditions along with other environmental variables can influence biological communities. Mussels are an ideal model species in nearshore estuarine communities to assess biological responses to environmental variability. The goal of this research is to answer the question which environmental variables correlate to mussel size frequency distributions in high latitude estuaries with and without glacial influence? This study sampled mussels at nine sites distributed across two regions (Lynn Canal and Kachemak Bay) and samples were taken over two years (2019 & 2020). Mussels were measured to the nearest mm and lengths were used to plot size frequency histograms for each site. Sites were grouped by hydrographic conditions from oceanic to riverine to glacial. Static environmental variables (i.e., substrate, slope and fetch, distance to freshwater and percent glaciation) were measured and calculated for each site, and a combination of linear regression models and multivariate analyses were used to determine the correlation between environmental variables and size frequency distributions for each site. These data were compared at the local (site to site) scale as well as at the regional (between regions) scale. Plotted with the mussel size frequencies, fetch and mud (small substrate) associated with sites with smaller mussel sizes, while larger substrate type, slope, and percent glaciation associated with other sites. These results suggest that mussels grow larger in larger substrates with less wave exposure.

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Food Web Ecology of Fishes Along a Gradient of Glacially Influenced Watersheds

Lindsey Stadler University of Alaska Fairbanks

Abstract: High-latitude systems magnify climate change effects that are being seen around the world with rising temperatures, increasing precipitation, and receding glaciers. Impacts linked with these changes such as increased freshwater flux into nearshore estuaries can potentially have major effects on food web dynamics and overall ecosystem functioning. The goal of this project is to quantify trophic responses in coastal fishes in glacially influenced watersheds. Fish are important ecosystem integrators and as median trophic levels may provide insight into how energy flow through trophic levels interconnects. Specifically, gunnels (Pholidae) as resident, location-bound species may serve as an excellent proxy for measuring both spatial (degrees of glacial discharge across multiple watersheds) and temporal (seasonal) effects of glacial melt on nearshore food web structure and energy flow. I am exploring spatial patterns of diet composition from stomach content analysis in gunnels from five watersheds with variable glacial coverage (from 0-60%) in Kachemak Bay. In addition, I compare diet composition from a season of peak glacial discharge to a season post-peak discharge.

Notes______Abstract: Estuarine habitats exhibit spatial and temporal variability due to fluctuating hydrological inputs and heterogenous coastal formations. Shifts in hydrology exacerbated by climate warming are leading to structural responses in nearshore estuarine fish communities driven by local conditions. To better understand relationships between physical factors and fish community structure, we conducted beach seine collections at multiple river mouth sites in Kachemak Bay during summer and fall of 2018. The effect of local conditions, spatial factors, and temporal factors were assessed in relation to community structure. Multivariate analyses examined how these factors accounted for variability in structure. An indicator value analysis identified species associations with spatial factors and month. Juvenile fishes made up 92% of the total catch confirming the importance of estuaries as nursery habitats. Site and month together best explained community variability. Bay location and current type had significant effects on structure. Month and bay location were characterized by spatiotemporal gradients in dissolved oxygen and turbidity, respectively. Juvenile Pacific herring (Clupea pallasii) were associated with inner bay conditions, while saffron cod (Eleginus gracilis) were associated with the outer bay. Juvenile Pacific salmon (Oncorhynchus spp.), starry flounder (Platichthys stellatus), and crescent gunnel (Pholis laetai) were associated with low current sites that were not well-defined by any measured physical factor. Adult and juvenile Pacific sand lance (Ammodytes hexapterus) were good indicators of both the inner bay and high current sites. Temporal patterns in species abundances confirmed results by prior studies of this area - juvenile salmonids appeared early, followed by juvenile gadids, and then sand lance later in the fall. Overall, variability in fish community structure was better explained by overarching spatial and temporal factors rather than by the local physical conditions. These results point to broader scale coastal shifts as potential mechanisms affecting community structure.

Notes______Abstract: Marine heatwaves are global phenomena that can have major impacts on the structure and function of coastal ecosystems. While offshore marine ecosystems are known to respond to these warmer waters, the response of rocky intertidal ecosystems to this warming is unclear. Intertidal communities link terrestrial and marine ecosystems and their resources are important to marine and terrestrial predators and to human communities for food and recreation, while simultaneously supporting a growing coastal tourism industry. Given that current climate change projections suggest increased frequency and duration of marine heatwaves, monitoring and understanding the impacts of heatwaves on intertidal habitats is important. As part of the Gulf Watch Alaska long-term monitoring program, we examined rocky intertidal community structure at 21 sites across four regions spanning 1,200 km of coastline: Western Prince William Sound, Kenai Fjords National Park, Kachemak Bay, and Katmai National Park and Preserve. Sites were monitored annually from 2012 to 2019 at mid and low tidal strata. Before the Pacific Marine Heatwave (2012-2014), community structure differed among regions. We found macroalgal foundation species declined during this period. The region-wide shift from an autotroph-macroalgal dominated rocky intertidal to a heterotroph-filter-feeder dominated state concurrent with the changing environmental conditions associated with a marine heatwave event suggests the PMH had Gulf-wide impacts to the structure of rocky intertidal communities. During/after the heatwave (2015-2019), similarities in community structure increased across regions, leading to a greater homogenization of these communities, due to declines in macroalgal cover. The pattern was driven mostly by a decline in the rockweed, Fucus distichus, and other fleshy red algae in 2015, followed by an increase in barnacle cover in 2016, and an increase in mussel cover in 2017. Strong, large-scale oceanographic events, like the PMH, may override local drivers to similarly influence patterns of intertidal community structure.

Notes______Abstract: Kachemak Bay waters support both open ocean and nearshore food webs, supported by primary production from phytoplankton and macroalgae such as kelp. Since 2012, researchers with the Gulf Watch Alaska program, funded by the Exxon Valdez Oil Spill Trustee Council, have monitored the bay’s ocean ecosystem with monthly shipboard oceanography surveys, and monitored the intertidal benthic ecosystem with annual surveys at multiple sites. These long-term time series are used to determine ecosystem response to climate variations and also examine linkages between the marine and nearshore ecosystems, including through meroplankton, the planktonic early life stages of benthic animals including clams, mussels, barnacles and sea stars. Changes in temperature conditions have been monitored with observations from long-term water quality stations in Seldovia and Homer harbors, ship surveys, and temperature sensors deployed at intertidal sampling sites. Intensive monthly monitoring of oceanography, phytoplankton and zooplankton (including meroplankton species) has been conducted with small boat surveys year-round in Kachemak Bay. The frequent sampling and bay-wide spatial coverage of the ship surveys allow tracking of seasonal and interannual changes in zooplankton species in conjunction with environmental changes. Annual nearshore intertidal monitoring in Kachemak Bay includes observations of percent cover of both mussels and barnacles, as well as density of sea stars. Results from oceanographic, zooplankton and intertidal species sampling show differences in timing of responses between plankton and benthic life stages for different species. Barnacle nauplii and cyprid plankton were most abundant in 2017, following an increase in adult populations starting in 2014. Conversely, bivalve veligers were most abundant in 2014 and 2015, while mussel percent cover increased later in 2018 and 2019. Research is ongoing to understand the impacts of the 2014-2016 Pacific heat wave on these ecosystem connections.

Notes______Abstract: Have you seen (or smelled) those piles of marine debris that wash onto the sandy beaches and rocky intertidal shores of Kachemak Bay? This is called beach wrack, and it is an important subsidy to coastal systems. Wrack is mostly composed of drifting marine seaweeds and is home to intertidal invertebrate communities and foraging shorebirds. Not only does wrack support a number of animals that rely on its relatively predictable accumulation, its predictability also offers itself as an accessible resource for people to collect for garden fertilizer. Aquatic plants, including those seaweeds found in wrack, are carefully regulated by the Alaska Department of Fish and Game, but there are some gray areas regarding the role that wrack plays on Alaskan beaches. The goal of our study is to provide managers with information on the ecological role of wrack so they can make informed decisions when crafting regulations on wrack harvests. Specific questions we are addressing include (1) How variable are accumulations of wrack among beaches over time? and (2) Which organisms may be impacted when wrack habitat is removed through harvesting efforts? To address these questions, from March to September 2021, we will re-visit a total of ten different beaches throughout Kachemak Bay to conduct monthly surveys on seaweed wrack, wrack-associated invertebrates, and migrating shorebirds. From previous work in 2018, we learned that wrack distribution and composition are highly variable among beaches, and that reproductive tissues of seaweeds in wrack can maintain function. Understanding this unique and ecologically important habitat is essential as it is also a natural resource with applications to human activity. The intention is not to prohibit wrack removal from beaches, rather we are encouraging sustainable harvests through a scientific approach of understanding how harvest timing might be used to mitigate impacts.

Notes______Abstract: Clam growth is known to influence a stock’s productivity or overall population dynamics via age at maturity, the time it takes for a clam to reach a harvestable size, harvestable biomass, fecundity, and mortality. Razor clam growth has been assessed in east Cook Inlet from age and length composition data from hand dug samples since the 1960’s. Initial comparisons were done by plotting age at length data while more rigorous assessment of growth have been conducted using Von Bertalanffy growth curves and growth performance indices. While Von Bertalanffy growth curves examines growth, the growth performance index provides a comparison of growth between beaches. Recently annual razor clam growth has been through calculating annual growth increments for every growth on every clam in the data set. Overall razor clam growth in east Cook Inlet decreases across beaches in a northerly direction with growth at Deep Creek being the fastest and the slowest at Cohoe (Nelson unpublished). It is assumed that east Cook Inlet razor clams primarily grow from April through October with little to no growth occurring throughout the remainder of the year (Mckellar 2014). Based on Von Bertalanffy growth curves, razor clam growth at Ninilchik beaches is more exponential than at Clam Gulch beaches in the first three years (Mckellar 2014). Using growth performance index has shown the clam growth on Ninilchik beaches had a higher performance index than Clam Gulch beaches (Kerkvliet et al 2021). Variable temporal periodicity in growth has been observed in east Cook Inlet beaches and growth of older ages within in a cohort was generally dependent on their size at age 3 (Blackmon et al. 2020). The environmental conditions that likely influences these observed variations in growth include circulation, temperature, salinity, phytoplankton availability, sediment composition and density dependence (Blackmon 2020). Although Mckellar (2014) found that both substrate and water temperatures at Clam Gulch and Ninilchik were similar throughout the year, the influences of these environmental conditions on growth have not been assessed with east Cook Inlet razor clams. Recent assessment of annual growth has shown that growth in 2017 and 2018 was well below any other year assessed at both Ninilchik and Clam Gulch beaches which has delayed the recovery of east Cook Inlet razor clams to support sport fishing harvest opportunities.

Notes______Abstract: How have the East Cook Inlet razor clams been faring since the sport and personal use fishery was closed in 2015? This presentation will provide an update on the abundances of juvenile and adult razor clams on two East Cook Inlet beaches, as well as other stock productivity indices including natural mortality rates and the recruitment of juvenile and adult razor clams. Since 2015, abundances of juvenile and adult razor clams have been surveyed annually at the Ninilchik South and Clam Gulch North beaches. In general, juvenile razor clam populations on these beaches are greater than the historical averages from prior to the fishery closure, while adult razor clam populations have remained below the historical averages. While a variety of factors are likely influencing both lifestages of razor clams on these beaches, including growth rates and predation, this presentation will focus on presenting the recent data that indicates annually high rates of natural mortality for both lifestages, variable but often high rates of juvenile recruitment, and below-average recruitment to the adult size.

Notes______Abstract: With rapidly changing marine ecosystems, shifts in abundance and distribution are being documented for a variety of intertidal species. We examined adjacent populations of Pacific razor clams (Siliqua patula) in lower Cook Inlet, Alaska, one (east) that supported a sport and personal use fishery but has been closed since 2015 due to declines in abundance, and a second (west) that continues to support commercial and sport fisheries. We used gene transcription to investigate potential causes of the east side decline, comparing razor clam physiological responses between east and west Cook Inlet. We identified no transcriptional differences between east and west populations, leading to two potential conclusions: (1) differences in factors capable of influencing physiology exist between east and west, and are sufficient to influence razor clam populations but are not detected by the genes in our panel, or (2) physiological processes do not account for the differences in abundance, and other factors such as predation or changes in habitat may be impacting the east Cook Inlet population. Habitat differences exist between east and west Cook Inlet, and the potential for habitat alteration is not uniform across all sites. Although we did not measure predation, top predators, particularly sea otters, are known to structure coastal marine communities. In east Cook Inlet, the collapse of razor clam fisheries may relate to recent recolonization by sea otters, while to the west sea otters remain rare and razor clam fisheries persist.

Notes______Abstract: The U.S. Fish and Wildlife Service (USFWS), the U.S. Geological Survey (USGS), and the Monterey Bay Aquarium have collaborated with Dr. Markus Horning (Wildlife Technology Frontiers) to develop a life history tag (LHX2) to collect survival and reproductive information in sea otters. Life history tags are internally implanted devices that collect and archive temperature, light, and motion data from the time of implantation to the death of the animal. Internal changes in these data can be linked to reproductive events and mortality events. We deployed 20 LHX2 tags in adult female sea otters in Kachemak Bay in 2019. We specifically selected Kachemak Bay because the area contains sufficient infrastructure that can facilitate monitoring and tag retrieval. We conceptualized this project as a proof of concept, allowing us to collect observations and locations on the animals, monitor pup production, and collect the LHX2 at the end of life while minimizing cost. We can then evaluate the tags and make changes before deploying these in the Southwest (SW) stock, which is currently listed as Threatened under the Endangered Species Act. The SW stock is located in the remote areas of the Aleutian management units, where little is known about sea otter demographic rates and where the lack of infrastructure makes traditional VHF-based monitoring studies logistically difficult or impossible. To date, four LHX2 tags have been released from animals showing successful transmissions of end of life data. Two mortality events were likely traumatic deaths, based on temperature, activity, and light sensor information collected. We have also been able to detect ovulation and parturition events in temperature data. We are continuing to monitor these tagged otters through aerial telemetry.

Notes______Abstract: The Fish and Wildlife Service (FWS) works closely with the Alaska Sea Life Center stranding network, student volunteers, and community members to assist with sea otter carcass disposal and data collection on carcasses, monitor reported sick otters, assist with animal rescue efforts , and oversee training of volunteers and students. Additionally, FWS authorizes the capture, rehabilitation, euthanasia, transportation and placement of non-releasable otters on a case-by case basis. Our main project objectives are to monitor trends in sea otter health and mortality and identify threats or anthropogenic impacts that may warrant management action. Carcasses are retrieved predominantly from the southcentral stock, particularly in Kachemak Bay where there are many tourists and an established network of volunteers, and a therefore a greater response effort. Additionally, the Kachemak Bay sea otter population is at carrying capacity, and therefore the high numbers of strandings observed are likely a density dependent response. In recent years, primary causes of death in this population were septicemia due to streptococcal infection ("Strep Syndrome") mostly attributed to S. lutetiensis, and trauma such as injury from inter-and intra-specific interactions, boat-strike, and gunshot wounds. Sea otter stranding trends and emerging concerns will be discussed, as well as ways the public can help.

Notes______Abstract: Sea otters (Enhydra lutris) are a federally protected species that have been recovering and reoccupying north Pacific coasts since they were nearly extirpated by commercial fur harvesting that ended in 1911. In addition, sea otter populations were adversely impacted by the 1989 Exxon Valdez Oil Spill in the northern Gulf of Alaska. As the sea otter continues to recover from anthropogenic stressors, it is necessary to understand their subtidal habitat requirements. This study used 2016/2017 National Oceanic and Atmospheric Administration drop camera footage and 2017 U.S. Fish and Wildlife Service aerial sea otter abundance survey data to draw associations of sea otters with habitat components, including substrate, algae, and invertebrates. It was found that boulder, cobble, pebble, sand, mud, kelp, filamentous/microalgae, crabs, sponges, sea stars, sea urchins, bryozoans, tunicates, and depth had significant positive and negative associations with sea otters. Additional variables, including currents, distance from shore, and rugosity, are being incorporated into the model. This work serves as a pilot study for additional research in Kachemak Bay, Katmai National Park, and Lake Clark National Park. Field work in 2021 will utilize a Remotely Operated Vehicle for subtidal surveys to model areas of sea otter population expansion into northern Cook Inlet based on habitat associations in Katmai National Park and Kachemak Bay. This research aims to aid management in light of oil and gas exploration and leasing activities and disaster response by providing comprehensive maps of current and potential sea otter habitats in the Cook Inlet lease area. Additionally, this study aims to expand the coastal habitat maps in Alaska and contribute to the growing field of geospatial survey technology.

Notes______Abstract:

Most of the world’s sea otters reside in Alaska, but there has never been an assessment of long-term mortality patterns for this keystone predator. We examined data collected from 780 northern sea otter (Enhydra lutris kenyoni) carcasses recovered in Alaska from 2002-2012 to evaluate the causes of mortality and risk factors associated with death. A smaller group (n = 144, 18%) of fresh non-frozen carcasses were included in a more detailed mortality analysis. Forty-four % of the fresh dead otters were determined to have died from infectious endocarditis, meningoencephalitis, and/or septicemia due to systemic streptococcosis (“Strep syndrome”). Streptococcus lutetiensis, a member of the Streptococcus bovis/equinus (SB/E) group was most commonly isolated, although other members of the SB/E group were identified. There were fewer cases where S. phocae and other streptococci were isolated. A regression analysis for Strep syndrome revealed that subadults were the highest risk age group, and otters recovered from the Kachemak Bay region were 3.6 times (95% CI: 2.2-5.9) more likely to die from Strep syndrome than otters recovered elsewhere. Diagnosis of this Strep syndrome had not been reported in other marine mammals in Alaska. Other causes of death include neurologic diseases (10%), trauma (8%), nutritional diseases (7%), cardiovascular diseases (7%), gastrointestinal diseases /parasites (6%), undetermined (5%), septicemia (3%), and neoplasia (3%). All other causes of death (oiling, hepatobiliary, fungal, marine biotoxins, pulmonary) were at or below 1%. Twenty percent of fresh animals were positive for phocine distemper virus (PDV) by polymerase chain reaction and paramyxovirus-like particles were demonstrated by electron microscopy within inclusion bodies Low concentrations of the harmful algal bloom toxins domoic acid and saxitoxin were also detected in 26% and 22% of fresh animals, respectively. Protozoal disease was rare. These patterns of disease differ from sea otters in other regions and possible reasons are discussed.

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Which came first? Linking ocean and nearshore ecosystems in Kachemak Bay, Alaska

Kris Holderied NOAA Kasitsna Bay Laboratory

Abstract: Kachemak Bay waters support both open ocean and nearshore food webs, supported by primary production from phytoplankton and macroalgae such as kelp. Since 2012, researchers with the Gulf Watch Alaska program, funded by the Exxon Valdez Oil Spill Trustee Council, have monitored the bay’s ocean ecosystem with monthly shipboard oceanography surveys, and monitored the intertidal benthic ecosystem with annual surveys at multiple sites. These long-term time series are used to determine ecosystem response to climate variations and also examine linkages between the marine and nearshore ecosystems, including through meroplankton, the planktonic early life stages of benthic animals including clams, mussels, barnacles and sea stars. Changes in temperature conditions have been monitored with observations from long-term water quality stations in Seldovia and Homer harbors, ship surveys, and temperature sensors deployed at intertidal sampling sites. Intensive monthly monitoring of oceanography, phytoplankton and zooplankton (including meroplankton species) has been conducted with small boat surveys year-round in Kachemak Bay. The frequent sampling and bay-wide spatial coverage of the ship surveys allow tracking of seasonal and interannual changes in zooplankton species in conjunction with environmental changes. Annual nearshore intertidal monitoring in Kachemak Bay includes observations of percent cover of both mussels and barnacles, as well as density of sea stars. Results from oceanographic, zooplankton and intertidal species sampling show differences in timing of responses between plankton and benthic life stages for different species. Barnacle nauplii and cyprid plankton were most abundant in 2017, following an increase in adult populations starting in 2014. Conversely, bivalve veligers were most abundant in 2014 and 2015, while mussel percent cover increased later in 2018 and 2019. Research is ongoing to understand the impacts of the 2014-2016 Pacific heat wave on these ecosystem connections.

Notes______Abstract: Southcentral Alaska has experienced unusually warm conditions over the past six years, which have manifested in persistent warming and freshening of the water column, increased mixed layer depths, and increased depths of the plankton chlorophyll maximum. Changes in water temperature and salinity can have drastic implications for birds, fish, and marine mammals. It disrupts the natural cycles of their critical food resources and facilitates harmful algal blooms. To understand ecosystem response to environmental drivers, we used oceanographic time-series data in Kachemak Bay, Alaska, to characterize the patterns of nearshore water conditions under seasonal and interannual timescales and how that variability compares to conditions over the past twenty years. Continuous oceanographic data from Kachemak Bay National Estuarine Research Reserve water quality stations and conductivity-temperature versus depth (CTD) profiler data from monthly shipboard surveys were used to assess nearshore and water column conditions. During the 2014-2016 pacific marine heatwave -often referred to as “the blob”- increasingly warmer winter temperatures, near or above 5˚C, lessened seasonal recovery, with two of the three subsequent years having a higher peak temperature than the last. Similarly, the winter of 2018-2019 was conspicuously warmer than that of the two years prior, near or above 5˚C, and the following summer was one of the warmest on record. Despite the record-setting summer, a cold air mass moved in across the state during fall 2019 and resulted in the drastic cooling of the water column through spring 2020. However, the seasonal cooling was temporary and did little to mitigate the following summer, where temperatures exceeded 10˚C throughout much of the water column. These data suggest that seasonal variability can strongly mitigate warming trends, but consistent cool temperatures may be necessary to temper the thermal mass of oceanic water bodies.

Notes______Abstract: Drifter trajectory data in lower Cook Inlet and Kachemak Bay from 2003 - 2007 and 2012 - 2017 are merged with more than 5600 hours of 2019 - 2020 drifter data from Kachemak Bay deployments to provide detailed information on the regional circulation. Maps of the mean, sub-tidal surface circulation were created from low-pass filtered velocities calculated from the drifter positions. The circulation pattern in inner Kachemak Bay shows one cyclonic cell in the east and one anti-cyclonic circulation cell near Homer Spit. The fastest surface currents are along the northern side of the inner Bay. The outer bay shows a large anti-cyclonic eddy with the eastern side flow merging into the generally northwest flow along the coast toward Anchor Point. To the west of this eddy, relatively low drifter densities suggest divergent flow. Based on the data acquired to date, several advective time scales are suggested relevant to larval or pollutant dispersal for Kachemak Bay and the Gulf of Alaska.

Notes______Abstract: As water flows over and through the land, it becomes enriched in a variety of dissolved materials before discharging into our coastal marine waters. These dissolved materials may be essential nutrients that spark growth of phytoplankton, or may be metals or contaminants that are harmful to marine organisms (or to those that feed on or harvest these organisms). In any case, we typically consider this discharge of water and dissolved material to be done predominantly by rivers. However, fluxes of material due to subsurface exchange between the land and the ocean, termed submarine groundwater discharge or SGD, are often found to outweigh inputs from rivers. Furthermore, tidally-driven pumping of seawater into and out of coastal sediments has been shown to be a major driver of SGD, suggesting that SGD may play an important role in delivering materials into Kachemak Bay. In investigate this, our group at UAF have begun measuring naturally-occurring radioisotope tracers that originate on land and enter the marine system at the land-ocean interface. By measuring these tracers alongside nutrients (nitrate/phosphate) and contaminants (mercury) in rivers, sediments, and seawater, we hope to understand the role of SGD in driving chemical, biological and ecological changes within Kachemak Bay.

Notes______Abstract: When studying coastal ecosystems, groundwater is often neglected. It can be tricky to quantify, so the focus is put on characterizing rivers. However, the flux of groundwater can be greater than rivers in many locations, and its dissolved nutrients can also differ. If we want to study a food web in a coastal environment, separating the inputs from rivers and groundwater can help us understand what is fueling the ecosystem. While groundwater is difficult to measure, we have two tools that we can use to characterize it. We can take advantage two naturally occurring elements, radon and radium, that enter the water from land-ocean boundaries. By using these elements as tracers, we can determine if groundwater is an important source in Kachemak Bay.

Notes______Abstract:

Nearshore ecosystems help to protect the coastline and provide important habitat for marine animals. Despite Alaska’s vast coastlines and vital fisheries, little is known about how ocean acidification (OA), a decline in ocean pH due to the absorption of anthropogenic carbon dioxide by the world's oceans, affects the nearshore environment. Because these ecosystems are highly dynamic and complex, it has been challenging to accurately monitor changes in ocean chemistry in coastal waters. Furthermore, with few baseline ocean pH records in place, it is difficult to determine the anthropogenic and natural influences on ocean pH variability. Current advances in pH sensor technology have led to OA monitoring networks along the west coast of the United States. One such network was established in Kachemak Bay, Alaska, in October 2017. pH, temperature, salinity and oxygen data were collected through October 2018, making this dataset one of the first records of nearshore, continuous, high-frequency pH measurements in coastal Alaska. These results demonstrate low wintertime pH variability followed by intense daily diel oscillations, with maximum summertime daily pH variability ranging between 0.1-0.3. Over a 12-month deployment period, the total pH variability was ~0.6, making Kachemak Bay one of the most naturally dynamic marine environments, with respect to pH, on record. Wintertime aragonite saturation state hovered at 1.5, above the threshold for calcium carbonate dissolution. In addition to documenting baseline pH measurements for this region, these data provide critical information with which studies can be designed to test the sensitivity of marine species to ocean acidification.

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Community Sampling for Ocean Acidification in South Central Alaska

Chelsea Campbell Chugach Regional Resources Commission

Abstract:

The ocean acidification program, conducted by the APMI and CRRC, has been bridging the gap between western science and residents of coastal communities in Southcentral Alaska. The continuous ocean acidification monitoring by APMI and discrete ocean acidification samples and exposure studies provide climate data for researchers to utilize in studying trends and high-level science. The discrete ocean acidification sampling program is conducted by Natural Resource Specialists in Alaska Native communities in Southcentral Alaska. This poster features data from the Native Village of Port Graham, the Native Village of Nanwalek, and the Seldovia Village Tribe, who have been building their capacities for years to manage local environmental protection programs. Utilizing local residents to conduct the sampling is a cost-effective way to expand the spatial ocean acidification dataset coverage, build capacity in those communities and broaden the local knowledge for residents most affected by changing ocean conditions. Continuing ocean acidification work is critical to understanding the effects of ocean acidification effects on important food resources for the Tribes in the Southcentral region. The community response and interest have been overwhelming and the interest outside the region also continues to grow. This poster is also intended to educate the samplers and leaders on the results to date and provide them the background needed to share the importance and results to residents of these communities. The data from the three participating communities (Port Graham, Nanwalek, and Seldovia) has provided the first opportunity to evaluate year-round water quality data. The data derived to date is useful as a baseline for the CRRC & APMI Water Quality Sampling Program, however, it is premature to make any conclusions or comparisons with one year of data.

Notes______Abstract: Many things changed in 2020. Marine debris, and the way we monitor remove it in Kachemak Bay is no exception. We will take a look at the data from the 2020 CoastWalk, an annual community effort to clean beaches and gather data on the marine debris found as well as environmental data. Information from 2020 will be compared to previous years both in how the cleanups were conducted as well as what was found during cleanups. Special focus will be placed on some rising areas of concern caused by the pandemic such as the potential increase of disposable PPE in the marine environment.

Notes______Abstract: Killer whales (Orcinus orca) are top predators in the North Pacific Ocean. The species is divided into three ecotypes—resident (primarily fish-eating), transient (mammal-eating), and offshore (largely shark-eating)â €”that are genetically and acoustically distinct and have unique impacts on the marine ecosystem. Killer whales use dialects of recognizable calls that can be used to discriminate between ecotype and often between pods. Passive acoustic monitoring is an effective tool to study the year-round habitat use and distribution patterns of killer whales because it is not limited by season or weather, duration of tag attachment, or animal welfare concerns, and is relatively inexpensive to operate for long-term monitoring. Passive acoustic monitoring efforts in Prince William Sound and Kenai Fjords over the last four years have already revealed several novel discoveries regarding killer whale habitat use. Pairing passive acoustic recordings from hydrophones in Prince William Sound with a field recording made in Kachemak Bay also allowed us to identify part of the dialect of a group of Gulf of Alaska transient killer whales—an important contribution as transient killer whales vocalize much less frequently than residents. We deployed a hydrophone in Kachemak Bay in August 2020, and retrieved and redeployed it in March 2021. The first batch of recordings is currently being processed to assess which days killer whales were present and identify the ecotype and pod, when possible. Preliminary results are expected soon.

Notes______Abstract: The Alaska Department of Fish and Game (ADF&G) manages black (Sebastes melanops) and yelloweye rockfish (S. ruberrimus) in Gulf of Alaska waters. Both species are important to sport and commercial fisheries statewide. In Kachemak Bay, Cook Inlet, and North Gulf Coast areas, commercial rockfish fisheries consist of a directed pelagic shelf rockfish fishery (primarily targets black rockfish) and mandatory retention of all rockfish species caught as bycatch (largest component is yelloweye rockfish). The guided and unguided sport fishery targets primarily black and yelloweye rockfish. Rockfish have life history characteristics (i.e. slow growth, longevity, and late maturation) that make them vulnerable to overexploitation, and increased harvest has been occurring in recent years in sport and commercial rockfish fisheries. Currently, rockfish management in the waters of Kachemak Bay, Cook Inlet, and the North Gulf Coast uses historic guideline harvest levels and is not based on comprehensive stock assessment methods to inform management decisions. However, with increased interest in rockfish fisheries, addressing concerns over sustainable management has become a top priority for ADF&G. In September 2017, ADF&G created the Statewide Rockfish Initiative (SRI) focused on developing long-term management strategies for black and yelloweye rockfish fisheries. SRI efforts are focused on creating statewide management standards and strategies, infrastructure, and knowledge that will support long-term adaptive management. Sport and commercial biological data, maturity work, age assessment, and comprehensive analyses of fishery removals, including modeling of fishing mortality levels to provide for sustainable fish populations, are integral components in developing long-term data driven management strategies for black and yelloweye rockfish in Gulf of Alaska waters.

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