Taking account of dependent species in management of the Southern Ocean krill fishery: estimating crabeater seal abundance off east Antarctica

1. The crabeater seal Lobodon carcinophaga is considered to be a key species in the krill-based food web of the Southern Ocean. Reliable estimates of the abundance of this species are necessary to allow the development of multispecies, predator–prey models as a basis for management of the krill fishery in the Southern Ocean. 2. A survey of crabeater seal abundance was undertaken in 1500 000 km2 of pack-ice off east Antarctica between longitudes 64–150° E during the austral summer of 1999/2000. Sighting surveys, using double observer line transect methods, were conducted from an icebreaker and two helicopters to estimate the density of seals hauled out on the ice in survey strips. Satellite-linked dive recorders were deployed on a sample of seals to estimate the probability of seals being hauled out on the ice at the times of day when sighting surveys were conducted. Model-based inference, involving fitting a density surface, was used to infer densities in the entire survey region from estimates in the surveyed areas. 3. Crabeater seal abundance was estimated to be between 0.7 and 1.4 million animals (with 95% confidence), with the most likely estimate slightly less than 1 million. 4. Synthesis and applications. The estimation of crabeater seal abundance in Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) management areas off east Antarctic where krill biomass has also been estimated recently provides the data necessary to begin extending from single-species to multispecies management of the krill fishery. Incorporation of all major sources of uncertainty allows a precautionary interpretation of crabeater abundance and demand for krill in keeping with CCAMLR’s precautionary approach to management. While this study focuses on the crabeater seal and management of living resources in the Southern Ocean, it has also led to technical and theoretical developments in survey methodology that have widespread potential application in ecological and resource management studies, and will contribute to a more fundamental understanding of the structure and function of the Southern Ocean ecosystem.

Climate Change and Water Resources Management: A Federal Perspective

Many challenges, including climate change, face the Nation’s water managers. The Intergovernmental Panel on Climate Change (IPCC) has provided estimates of how climate may change, but more understanding of the processes driving the changes, the sequences of the changes, and the manifestation of these global changes at different scales could be beneficial. Since the changes will likely affect fundamental drivers of the hydrological cycle, climate change may have a large impact on water resources and water resources managers. The purpose of this interagency report prepared by the U.S. Geological Survey (USGS), U.S. Army Corps of Engineers (USACE), Bureau of Reclamation (Reclamation), and National Oceanic and Atmospheric Administration (NOAA) is to explore strategies to improve water management by tracking, anticipating, and responding to climate change. The key points below briefly summarize the chapters in this report and represent underlying assumptions needed to address the many impacts of climate change.

Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells

The U.S. Geological Survey (USGS) is committed to providing the Nation with credible scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov/). Information on the Nation’s water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation and is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of that water, now measured in terms of quantity and quality, even more essential to the long-term sustainability of our communities and ecosystems. The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, State, and local information needs and decisions related to water-quality management and policy (http://water.usgs.gov/nawqa). The NAWQA Program is designed to answer: What is the condition of our Nation’s streams and ground water? How are conditions changing over time? How do natural features and human activities affect the quality of streams and ground water, and where are those effects most pronounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. From 1991-2001, the NAWQA Program completed interdisciplinary assessments and established a baseline understanding of water-quality conditions in 51 of the Nation’s river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/studyu.html).

EC31-133 The Management of Nebraska Soils (Revised March 1936)

The agricultural lands of this country are its greatest natural resource. History points out that nations with vast areas of good farm land are most likely to prosper and survive over long periods of time. Local communities, too, prosper and flourish in proportion to the productiveness of the surrounding land. Schools, social life, and business develop best in areas where the land is productive and properly managed and conserved. Nebraska, in common with other states, has suffered by the depletion of soil fertility. The reduction in acres in legumes and grasses, and the deplation of the organic matter in the surface soils, has likewise had its effect on the run-off of precipitation, soil blowing, and damage from drouth. In order to know what elements of fertility may become deficient and how soil fertility may be restored and maintained, we should understand the composition, character, and management of soils. In the following pages, some fundamentals of soil feritlity are given, followed later by a discussion of practical soil-management practices.

Ecology, stable isotopes, and management of grassland songbirds at National Park Service properties on the Great Plains

Grassland ecosystems have been severely reduced and grassland bird populations have experienced consistent declines. National Park Service (NPS) properties on the Great Plains provide breeding habitat for grassland songbirds, though little is known about the quality of this habitat. A short-term study on songbirds at three NPS properties complemented current monitoring, providing an among park comparison addressing grassland bird productivity and fidelity relative to NPS property size. During 2008-2009, I assessed avian species richness, and estimated bird density and grassland songbird nest success. Bird species richness was greatest at small and medium sites, while number of nesting obligate species was greatest at the large site. Species-specific densities varied among sites, with few grassland obligates occurring at all three sites. Nest success estimates for grassland obligates were highest at the small site and lower at the large site. Another method to quantify habitat quality is assessment of breeding site fidelity. Current extrinsic markers used in monitoring site fidelity are inadequate for small birds; stable isotope analyses provide an alternative. I compared two techniques for assigning stable isotope tissue origin and measured grassland songbird site fidelity. My method of assigning origin provided site-specific variances of expected stable isotope values, an improvement over the most commonly used method. Fidelity tended to be higher at the large site, which may indicate a more robust breeding community of grassland birds. The small size of two of my sites precluded large sample sizes and made strong inferences difficult. To quantify how scientists cope with weak inference, I conducted a literature review. Strong inference was rarely observed, and most authors of weak-inference papers provided specific management recommendations. I suggest that adaptive management is an ideal method to resolve uncertainty from weak inference. Managers should consider my results within the context of regional and global management and the extent to which their unit might aide songbird conservation.

Distribution of Rain Gardens in Lincoln Nebraska: Are Rain Gardens more Likely to be Built Near Bodies of Water

Abstract Rain gardens are an important tool in reducing the amount of stormwater runoff and accompanying pollutants from entering the city’s streams and lakes, and reducing their water quality. This thesis project analyzed the number of rain gardens installed through the City of Lincoln Nebraska Watershed Management’s Rain Garden Water Quality Project in distance intervals of one-eighth mile from streams and lakes. This data shows the distribution of these rain gardens in relation to streams and lakes and attempts to determine if proximity to streams and lakes is a factor in homeowners installing rain gardens. ArcGIS was used to create a map with layers to determine the number of houses with rain gardens in 1/8 mile distance increments from the city’s streams and lakes and their distances from a stream or lake. The total area, number of house parcels, and the type and location of each parcel type were also determined for comparison between the distance interval increments. The study revealed that fifty-eight percent of rain gardens were installed within a quarter mile of a stream or lake (an area covering 60% of the city and including 58.5% of the city’s house parcels), and that eighty percent of rain gardens were installed within three-eighth mile of streams or lakes (an area covering 75% of the city and 78.5% of the city’s house parcels). All parcels in the city are within 1 mile of a stream or lake. Alone the number of project houses per distance intervals suggested that proximity to a stream or lake was a factor in people’s decisions to install rain gardens. However, when compared to the number of house parcels available, proximity disappears as a factor in project participation.

A Survery of Western United States Instream Flow Programs and The Policies that Protect a River's Ecosystem

The Western United States can best be described as a vast, varying land, with the high plains to the east and the jagged horizons of Rockies to the west. However there is one common trait shared by these states: the lack of water resources. With the continued development of this land, the fact that water is scarce is becoming more real. This issue became more difficult to handle as the public became more aware that many competing uses existed for the finite resource, and those different uses were degrading the natural environments of the surface waters. With this realization instream flow policies provides a comprehensive account of the policy framework a selected number of western states have established in order to protect instream flows and the overall health of a river's ecosystem. Also included is the identification of key policies that should be promoted or removed from a state's instream flow program. Ultimately, this thesis continues to add the the ever-evolving process of modernizing water law frameworks.