Coastal Lagoon Community and Ecological Monitoring in the Southern Chukchi Sea National Park Units ~ 2015 Field Sampling Report ~

Haynes, Trevor; Robards, Martin; Tibbles, Marguerite; Jones, Tahzay; Whiting, Alex; Wipfli, Mark

Wildlife Conservation Society (WCS) provides assistance to the National Park Service with the design and implementation of the Coastal Lagoon Vital Sign component of the Inventory and Monitoring Program. Our 2015 field effort was a continuation of the Vital Sign Program. This program is intended to establish biotic and abiotic reference conditions for coastal lagoons in Cape Krusenstern National Monument and Bering Land Bridge National Preserve. The Vital Sign Program is still being developed for lagoons, and our 2015 effort will be used to inform the creation of a standardized protocol to monitor lagoon vital signs. These vital signs will focus on monitoring the structure and function of lagoons and fish resources used for subsistence by coastal communities. Our 2015 sampling was supplemented by Coastal Settlement Funds focused on better documentation of whitefish ecology in the lagoons, and provided the additional capacity necessary for collecting seasonal (rather than a rapid single visit) water quality data; fish sampling and assessing the feasibility of adding coverage of the vital sign program to the lagoon at Cape Espenberg. Fish research focused on whitefish and species of ecological importance and included sampling of community composition, seasonal and spatial patterns of use, trophic dynamics, and fish health. As part of the Vital Signs program, we monitored water quality through the season (3-5 times total per lagoon) at the 3 lagoons in Cape Krusenstern, and once for the 2 lagoons in Bering Land Bridge. At each lagoon visit, we used a small inflatable boat equipped with a 9.9 horsepower outboard motor to visit four long-term (Center, Outflow, Inflow, and Adjacent-to-the-Ocean stations) and three random stations in each lagoon and accessed Park units via fixed-wing plane (tundra tire or float). We also sampled water quality in the protected waters at Cape Espenberg; however, extremely shallow water throughout (< 30cm) limited our ability to conduct standardized data collection at that site. Ease of access and logistics allowed us to sample the lagoons in Cape Krusenstern more frequently, whereas, we sampled the lagoons in Bering Land Bridge only once, due to both challenging access and the costs of dedicated long flights out of Kotzebue. Physical water properties varied by lagoon and season. The salinity of the lagoon appears to be related to its connection with the marine environment; the more connected the lagoon is to the Chukchi Sea, the higher its salinity. For example, Krusenstern Lagoon, which has a small connection that is intermittently open to the marine, is far more fresh (2.1 ppt) compared with lagoons that have large connections to the Chukchi Sea that remain open throughout the year, such as Espenberg Lagoon (31.9 ppt). For the three lagoons that were monitored periodically throughout the summer (Krusenstern, Aukulak and Kotlik) we noted general seasonal trends, included a decrease in temperature and pH, and an increase in dissolved oxygen from July to September. Whitefish captured during the 2015 field season included sheefish, humpback whitefish, least cisco and Bering cisco. We collected fish length and otolith samples to examine fish growth rates for resident and migratory species. While our focus was on standardized seasonal characterization of water properties and of whitefish ecology, we also gathered length-weight measurements and otoliths from pond smelt (Hypomesus olidus), a poorly studied species which we recorded in Cape Krusenstern and Bering Land Bridge lagoons for the first time this season. Pond smelt were locally abundant and consequently may play an important role in the trophic dynamics in certain lagoons, such as Krusenstern Lagoon. We assessed stomach contents on 14 species, focusing on key species in the lagoons. For larger fish, to minimize research mortality, we used gastric lavage. Our preliminary findings show that mysids, chironomids and ninespine stickleback are the three major prey items consumed by fish. To examine fish health, we are partnering with the State of Alaska to analyze contaminants (metals and organic contaminants) in 9 species (Bering cisco, fourhorn sculpin, humpback whitefish, least cisco, ninespine stickleback, Pacific herring, saffron cod, sheefish, starry flounder), collected from the three lagoons in Cape Krusenstern. Data we collected in 2015 builds on prior traditional knowledge and scientific research, provides ecological information vital for monitoring and managing Arctic lagoons of these Park units, helps prioritize spill contingency planning (by establishing the most productive lagoons), and will continue to inform a comprehensive understanding of the Story of the Lagoons – a key priority for the Native Village of Kotzebue, Wildlife Conservation Society, and the National Park Service.

Coastal Lagoon Community and Ecological Monitoring in the Southern Chukchi Sea National Park Units ~ 2015 Field Sampling Report ~

See also