The Effects of Tropical Storm Agnes on Fishes in the James, York, and Rappahannock Rivers of Virginia

Intensive trawl surveys during and after Tropical Storm Agnes were mounted on the James, York, and Rappahannock Rivers to measure the effects of the floodwaters on the distribution and abundance of fish. The direct effect of Agnes on the fish populations was minor and temporary. The normal zone was extended downriver. A substantial portion of the lower-river (marine) species was also displaced downstream and into Chesapeake Bay, but had returned by the follow-up surveys. No adult mortalities due to Agnes were detected. Although we know vast quantities of fish larvae and other plankton were swept into Chesapeake Bay, the overall impact on all fish appears to have been slight.https://scholarworks.wm.edu/vimsbooks/1073/thumbnail.jp

MITOCHONDRIAL CHANGES IN THE LIVER OF ESSENTIAL FATTY ACID-DEFICIENT MICE

Livers of mice on diets deficient in essential fatty acids (EFA) have been studied by light and electron microscopy. The most conspicuous changes occur in the mitochondria. In light microscopy the mitochondria appear very much enlarged in the periportal region of the lobule. In electron micrographs they have additional cristae, sometimes very abundant. ranged in stacks in the central cavity. The matrix may be more electron-opaque than normal. This is in contrast with the enlarged mitochondria appearing under other experimental conditions, where the cristae are reduced in number and the matrix is less electron-opaque. It is known that there is an uncoupling of oxidative phosphorylation in EFA-deficient mitochondria. As a hypothesis it is proposed that the uncoupling may be due to a molecular defect caused by the absence of EFA in the structure that determines the spatial relationship between the electron transport chain and oxidative phosphorylation. It is further tentatively suggested that the changes in mitochondria may be attributed to lack of ATP. The possibility is discussed that the mitochondrial changes are ineffective attempts at compensation for this lack

Indigenous Knowledge of Hydrologic Change in the Yukon River Basin: A Case Study of Ruby, Alaska

In the Arctic and Subarctic, the contribution of Indigenous knowledge to understanding environmental change has been established over the last several decades. This paper explores the role of Indigenous knowledge of water in understanding hydrologic change within complex social-ecological systems. Observations of hydrology in the Yukon River Basin, contributed by 20 community experts from Ruby Village, Alaska, in semi-structured interviews, are compared with findings from scientific literature to illustrate the commonalities and differences. Research findings reveal the contribution of Indigenous knowledge to understandings of hydrologic change in the Yukon River and its tributaries, which includes insights regarding alterations in sediment and river ice regimes. Recommendations for future research that incorporates Indigenous knowledge of water to gain insight into hydrologic changes in the watershed include combining multiple case studies that are distributed geographically. Our findings suggest 1) that using participatory research approaches to research will help ensure that it benefits the communities whose livelihoods are affected by hydrologic changes, and 2) that a multidisciplinary approach that combines qualitative and quantitative methods from the social and biophysical sciences would be most effective to help us understand and respond to hydrologic changes.Dans l’Arctique et la région subarctique, l’apport des connaissances indigènes à l’égard de la compréhension de l’altération de l’environnement a été mis au clair au cours des dernières décennies. Cette communication explore le rôle des connaissances indigènes relativement à l’eau dans la compréhension des changements hydrologiques touchant les systèmes socioécologiques complexes. Les observations hydrologiques dans le bassin du fleuve Yukon, émanant de 20 experts communautaires de Ruby Village, en Alaska et prélevées dans le cadre d’entrevues semi-structurées, sont comparées aux constatations publiées dans des documents scientifiques pour illustrer les points communs et les différences. Les résultats de recherche révèlent l’apport des connaissances indigènes en matière de compréhension des changements hydrologiques caractérisant le fleuve Yukon et ses affluents, ce qui comprend un aperçu de l’altération des sédiments et des régimes de glaces fluviales. Les recommandations de recherches futures faisant appel aux connaissances indigènes de l’eau afin de mieux comprendre les changements hydrologiques du bassin hydrographique préconisent le fait de combiner de nombreuses études de cas géographiquement réparties. Nos constatations suggèrent 1) que le recours à des méthodes de recherche participative aidera à faire en sorte que les collectivités dont le mode de vie est touché par les changements hydrologiques bénéficient des travaux de recherche, et 2) qu’une approche multidisciplinaire dans les domaines des sciences sociales et biophysiques faisant appel à la fois à des méthodes qualitatives et à des méthodes quantitatives s’avérerait plus efficace, et nous aiderait à comprendre les changements hydrologiques puis à y réagir