The resource appraisal survey of clupeids in Kainji Lake, Nigeria

This study includes an analysis of the trawl survey that was carried out by the Kainji Lake Fisheries Promotion Project in May, 1997. The objective of the survey was to assess the biomass and the potential yield of clupeids and the carrying capacity of the beach seine fishery in the entire Kainji Lake (Nigeria). The biomass of the beach seine by-catch was also estimated. The density (kg /km super(3)) of the clupeids was higher in the Bussa and Foge than in the other stations. The lowest density of clupeids was in the Anfani station followed by Jetty, both in the southern basin. These stations were the deepest parts of all the areas trawled, measuring between 37-120 m of depth. There was an inverse correlation between depth trawled and the catch rates of clupeids, though the correlation was poor. The average annual biomass of the clupeids was estimated at 36,769.85 Mt in the entire Lake with an MSY of 11,705.95 Mt. The smaller species, Sierrathrissa leonensis, made up about 97% of the total clupeid population in the lake and occurred at a shallower depth than the larger species Pellonula afzeliusi. From the clupeid production statistics in 1996, it is estimated that the MSY is already overshot by 34%. Therefore, about 698 beach seines instead of the present 810 would be sufficient for sustainable exploitation of the clupeid stocks. Because of the substantial by-catch in the beach seines, this fishing method was banned from Kainji Lake in 1997. An offshore open water seine net is recommended to replace the beach seines on the lake. The number of these nets should not exceed 500. The current ban on beach seine is supported by this study. Nevertheless, and since the ban may not be 100% effective, effort should concentrate on maintaining that the number of beach seines must be kept at most at the present level. Recommendation is made against the introduction of the pair trawling not only from an economic point of view but also for resource conservation, legal and social reasons. The development of this fishery could pose a serious danger to continuity of stocks. It is proposed that priority be given to the development of an open water seine which is at the same level of exploitation as the beach seine and requires similar cost to acquire. (PDF contains 39 pages)

Fisheries statistics of Kainji Lake, northern Nigeria, Nov. 1994 - Dec. 1998

Results are presented for the first 4 years data (1994-1998) of the Kainji Lake catch assessment survey, collected and analysed by the Nigerian-German Kainji Lake Fisheries Promotion Project. The following areas are covered: Methodology and alterations of the original sampling concept; Frame survey results - factors relating to the CAS; Catch assessment survey results - general; Gill net fishery; Drift net fishery; Beach seine fishery; Cast net fishery; Longline fishery; Trap fishery; and, Catch statistics from fisherwomen. (PDF contains 143 pages)

Predictions of fish yields and the status of the Kainji Lake fishery, 1998

Length frequency data was collected for the 6 main species from the Kainji Lake fishery for up to 16 months. Growth parameters were estimated and used for virtual - population and length based cohort analysis. The results from cohort analysis suggest that before the ban on beach seines the maximum economic yield from the fishery was overshot by 70%. Yield per recruit analysis showed that the fish are caught far below their optimum size. Fishing gears and the timing responsible for this early mortality have been identified. After the eradication of seines from the lake a 10% increase in total catch revenue can be expected from the fishery. This is equivalent to an increase in income of Naira 18,300 per annum for each fishing entrepreneur using other methods. A scenario for the regulation of cast net mesh size together with the ban of beach seines has been presented. A further increase of Naira 142 million (N25,500 per entrepreneur) can be anticipated if this is implemented by the Kainji Lake Fisheries Management and Conservation Unit. It is expected that the annual increase in fishing effort presently experienced will cause future yields to decline. The rate of the decline has been reduced by the eradication of the beach seine fishery and will further fall if the minimum mesh size for cast nets is implemented. A recommendation is made to the Kainji Lake Fisheries Management and Conservation Unit to first consolidate the beach seine ban and then to implement a ban of undersized cast nets. (PDF contains 70 pages)

Deepwater shorelines

Research has proven that Shoreline Erosion is caused by excess water contained within the shore face. This Research presents an opportunity to control erosion by managing the near shore water table. Our Research on Bogue Banks North Carolina suggests that our buildings and other impervious surfaces collect and concentrate water from storm rain runoff into the surface water table and within the critical beach front water exit point. Presently our Potable Fresh Water is supplied from deep wells located beneath an impervious layer of Marl. After our use, the Waste water is drained into the Surface Aquifer, the combined waste and storm rain water raises the Surface Aquifer water table and produces Erosion. The Deep Aquifers presently supplying our Potable Water have an unknown recharge rate, with increasing reports of Salt Water intrusion. We believe our Vital Fresh water supply system should be modified to supply Reverse Osmosis treatment plants from shallow wells. This will lower the Surface Water Table. These Shallow wells, either horizontal or vertical, might be located within the beach front, adjacent to high erosion risk properties. Beach Drains and Reverse Osmosis Water systems are new and proven technologies. By combining these technologies we can reduce or reverse Shore Erosion, ensure a safe Potable Water supply, reduce requirements for periodic beach nourishment, reduce taxes and protect our property well into the Future. (PDF contains 5 pages)

Sea-level rise in Hawaii: Implications for future shoreline locations and Hawaii coastal management

Management of coastal development in Hawaii is based on the location of the certified shoreline, which is representative of the upper limit of marine inundation within the last several years. Though the certified shoreline location is significantly more variable than long-term erosion indicators, its migration will still follow the coastline's general trend. The long-term migration of Hawaii’s coasts will be significantly controlled by rising sea level. However, land use decisions adjacent to the shoreline and the shape and nature of the nearshore environment are also important controls to coastal migration. Though each of the islands has experienced local sea-level rise over the course of the last century, there are still locations across the islands of Kauai, Oahu, and Maui, which show long- term accretion or anomalously high erosion rates relative to their regions. As a result, engineering rules of thumb such as the Brunn rule do not always predict coastal migration and beach profile equilibrium in Hawaii. With coastlines facing all points of the compass rose, anthropogenic alteration of the coasts, complex coastal environments such as coral reefs, and the limited capacity to predict coastal change, Hawaii will require a more robust suite of proactive coastal management policies to weather future changes to its coastline. Continuing to use the current certified shoreline, adopting more stringent coastal setback rules similar to Kauai County, adding realistic sea-level rise components for all types of coastal planning, and developing regional beach management plans are some of the recommended adaptation strategies for Hawaii. (PDF contains 4 pages)

Reforming state-level coastal management and development policies: strategic retreat as an innovative, proactive and equitable coastal environmental management strategy

Atlantic and Gulf Coast shorelines include some of the most unique and biologically rich ecosystems in the United States that provide immeasurable aesthetic, habitat and economic benefits. Natural coastal ecosystems, however, are under increasing threat from rampant and irresponsible growth and development. Once a boon to local economies, complex natural forces – enhanced by global climate change and sea level rise - are now considered hazards and eroding the very foundation upon which coastal development is based. For nearly a century, beach restoration and erosion control structures have been used to artificially stabilize shorelines in an effort to protect structures and infrastructure. Beach restoration, the import and emplacement of sand on an eroding beach, is expensive, unpredictable, inefficient and may result in long-term environmental impacts. The detrimental environmental impacts of erosion control structures such as sea walls, groins, bulkheads and revetments include sediment deficits, accelerated erosion and beach loss. These and other traditional responses to coastal erosion and storm impacts- along with archaic federal and state policies, subsidies and development incentives - are costly, encourage risky development, artificially increase property values of high-risk or environmentally sensitive properties, reduce the post-storm resilience of shorelines, damage coastal ecosystems and are becoming increasingly unsustainable. Although communities, coastal managers and property owners face increasingly complex and difficult challenges, there is an emerging public, social and political awareness that, without meaningful policy reforms, coastal ecosystems and economies are in jeopardy. Strategic retreat is a sustainable, interdisciplinary management strategy that supports the proactive, planned removal of vulnerable coastal development; reduces risk; increases shoreline resiliency and ensures long term protection of coastal systems. Public policies and management strategies that can overcome common economic misperceptions and promote the removal of vulnerable development will provide state and local policy makers and coastal managers with an effective management tool that concomitantly addresses the economic, environmental, legal and political issues along developed shorelines. (PDF contains 4 pages)

If the tide is rising, who pays for the ark?

Two common goals of this meeting are to arrest the effects of sea level rise and other phenomena caused by Greenhouse Gases from anthropogenic sources ("GHG",) and to mitigate the effects. The fundamental questions are: (1) how to get there and (2) who should shoulder the cost? Given Washington gridlock, states, NGO's and citizens such as the Inupiat of the Village of Kivalina have turned to the courts for solutions. Current actions for public nuisance seek (1) to reduce and eventually eliminate GHG emissions, (2) damages for health effects and property damage—plus hundreds of millions in dollars spent to prepare for the foregoing. The U.S. Court of Appeals just upheld the action against the generators of some 10% of the CO2 emissions from human activities in the U.S., clearing the way for a trial featuring the state of the art scientific linkage between GHG production and the effects of global warming. Climate change impacts on coastal regions manifest most prominently through sea level rise and its impacts: beach erosion, loss of private and public structures, relocation costs, loss of use and accompanying revenues (e.g. tourism), beach replenishment and armoring costs, impacts of flooding during high water events, and loss of tax base. Other effects may include enhanced storm frequency and intensity, increased insurance risks and costs, impacts to water supplies, fires and biological changes through invasions or local extinctions (IPCC AR4, 2007; Okmyung, et al., 2007). There is an increasing urgency for federal and state governments to focus on the local and regional levels and consistently provide the information, tools, and methods necessary for adaptation. Calls for action at all levels acknowledge that a viable response must engage federal, state and local expertise, perspectives, and resources in a coordinated and collaborative effort. A workshop held in December 2000 on coastal inundation and sea level rise proposes a shared framework that can help guide where investments should be made to enable states and local governments to assess impacts and initiate adaptation strategies over the next decade. (PDF contains 5 pages)

Local solutions to local problems: A stormwater education collaborative

Currently completing its fifth year, the Coastal Waccamaw Stormwater Education Consortium (CWSEC) helps northeastern South Carolina communities meet National Pollutant Discharge Elimination System (NPDES) Phase II permit requirements for Minimum Control Measure 1 - Public Education and Outreach - and Minimum Control Measure 2 - Public Involvement. Coordinated by Coastal Carolina University, six regional organizations serve as core education providers to eight coastal localities including six towns and cities and two large counties. CWSEC recently finished a needs assessment to begin the process of strategizing for the second NPDES Phase II 5-year permit cycle in order to continue to develop and implement effective, results-oriented stormwater education and outreach programs to meet federal requirements and satisfy local environmental and economic needs. From its conception in May 2004, CWSEC set out to fulfill new federal Clean Water Act requirements associated with the NPDES Phase II Stormwater Program. Six small municipal separate storm sewer systems (MS4s) located within the Myrtle Beach Urbanized Area endorsed a coordinated approach to regional stormwater education, and participated in a needs assessment resulting in a Regional Stormwater Education Strategy and a Phased Education Work Plan. In 2005, CWSEC was formally established and the CWSEC’s Coordinator was hired. The Coordinator, who is also the Environmental Educator at Coastal Carolina University’s Waccamaw Watershed Academy, organizes six regional agencies who serve as core education providers for eight coastal communities. The six regional agencies working as core education providers to the member MS4s include Clemson Public Service and Carolina Clear Program, Coastal Carolina University’s Waccamaw Watershed Academy, Murrells Inlet 2020, North Inlet-Winyah Bay National Estuarine Research Reserve’s Coastal Training and Public Education Programs, South Carolina Sea Grant Consortium, and Winyah Rivers Foundation’s Waccamaw Riverkeeper®. CWSEC’s organizational structure results in a synergy among the education providers, achieving greater productivity than if each provider worked separately. The member small MS4s include City of Conway, City of North Myrtle Beach, City of Myrtle Beach, Georgetown County, Horry County, Town of Atlantic Beach, Town of Briarcliffe Acres, and Town of Surfside Beach. Each MS4 contributes a modest annual fee toward the salary of the Coordinator and operational costs. (PDF contains 3 pages)

San Francisco Bay regional sediment management strategy development

The San Francisco Bay Conservation and Development Commission (BCDC), in continued partnership with the San Francisco Bay Long Term Management Strategies (LTMS) Agencies, is undertaking the development of a Regional Sediment Management Plan for the San Francisco Bay estuary and its watershed (estuary). Regional sediment management (RSM) is the integrated management of littoral, estuarine, and riverine sediments to achieve balanced and sustainable solutions to sediment related needs. Regional sediment management recognizes sediment as a resource. Sediment processes are important components of coastal and riverine systems that are integral to environmental and economic vitality. It relies on the context of the sediment system and forecasting the long-range effects of management actions when making local project decisions. In the San Francisco Bay estuary, the sediment system includes the Sacramento and San Joaquin delta, the bay, its local tributaries and the near shore coastal littoral cell. Sediment flows from the top of the watershed, much like water, to the coast, passing through rivers, marshes, and embayments on its way to the ocean. Like water, sediment is vital to these habitats and their inhabitants, providing nutrients and the building material for the habitat itself. When sediment erodes excessively or is impounded behind structures, the sediment system becomes imbalanced, and rivers become clogged or conversely, shorelines, wetlands and subtidal habitats erode. The sediment system continues to change in response both to natural processes and human activities such as climate change and shoreline development. Human activities that influence the sediment system include flood protection programs, watershed management, navigational dredging, aggregate mining, shoreline development, terrestrial, riverine, wetland, and subtidal habitat restoration, and beach nourishment. As observed by recent scientific analysis, the San Francisco Bay estuary system is changing from one that was sediment rich to one that is erosional. Such changes, in conjunction with increasing sea level rise due to climate change, require that the estuary sediment and sediment transport system be managed as a single unit. To better manage the system, its components, and human uses of the system, additional research and knowledge of the system is needed. Fortunately, new sediment science and modeling tools provide opportunities for a vastly improved understanding of the sediment system, predictive capabilities and analysis of potential individual and cumulative impacts of projects. As science informs management decisions, human activities and management strategies may need to be modified to protect and provide for existing and future infrastructure and ecosystem needs. (PDF contains 3 pages)

Adapting to climate change: Combining economics and geomorphology in coastal policy

How is climate change affecting our coastal environment? How can coastal communities adapt to sea level rise and increased storm risk? These questions have garnered tremendous interest from scientists and policy makers alike, as the dynamic coastal environment is particularly vulnerable to the impacts of climate change. Over half the world population lives and works in a coastal zone less than 120 miles wide, thereby being continuously affected by the changes in the coastal environment [6]. Housing markets are directly influenced by the physical processes that govern coastal systems. Beach towns like Oak Island in North Carolina (NC) face severe erosion, and the tax assesed value of one coastal property fell by 93% in 2007 [9]. With almost ninety percent of the sandy beaches in the US facing moderate to severe erosion [8], coastal communities often intervene to stabilize the shoreline and hold back the sea in order to protect coastal property and infrastructure. Beach nourishment, which is the process of rebuilding a beach by periodically replacing an eroding section of the beach with sand dredged from another location, is a policy for erosion control in many parts of the US Atlantic and Pacific coasts [3]. Beach nourishment projects in the United States are primarily federally funded and implemented by the Army Corps of Engineers (ACE) after a benefit-cost analysis. Benefits from beach nourishment include reduction in storm damage and recreational benefits from a wider beach. Costs would include the expected cost of construction, present value of periodic maintenance, and any external cost such as the environmental cost associated with a nourishment project (NOAA). Federal appropriations for nourishment totaled $787 million from 1995 to 2002 [10]. Human interventions to stabilize shorelines and physical coastal dynamics are strongly coupled. The value of the beach, in the form of storm protection and recreation amenities, is at least partly capitalized into property values. These beach values ultimately influence the benefit-cost analysis in support of shoreline stabilization policy, which, in turn, affects the shoreline dynamics. This paper explores the policy implications of this circularity. With a better understanding of the physical-economic feedbacks, policy makers can more effectively design climate change adaptation strategies. (PDF contains 4 pages)

Coastal erosion as a natural resource management problem: An economic perspective

Unremitting waves and occasional storms bring dynamic forces to bear on the coast. Sediment flux results in various patterns of erosion and accretion, with an overwhelming majority (80 to 90 percent) of coastline in the eastern U.S. exhibiting net erosion in recent decades. Climate change threatens to increase the intensity of storms and raise sea level 18 to 59 centimeters over the next century. Following a lengthy tradition of economic models for natural resource management, this paper provides a dynamic optimization model for managing coastal erosion and explores the types of data necessary to employ the model for normative policy analysis. The model conceptualizes benefits of beach and dune sediments as service flows accruing to nearby residential property owners, local businesses, recreational beach users, and perhaps others. Benefits can also include improvements in habitat for beach- and dune-dependent plant and animal species. The costs of maintaining beach sediment in the presence of coastal erosion include expenditures on dredging, pumping, and placing sand on the beach to maintain width and height. Other costs can include negative impacts on the nearshore environment. Employing these constructs, an optimal control model is specified that provides a framework for identifying the conditions under which beach replenishment enhances economic welfare and an optimal schedule for replenishment can be derived under a constant sea level and erosion rate (short term) as well as an increasing sea level and erosion rate (long term). Under some simplifying assumptions, the conceptual framework can examine the time horizon of management responses under sea level rise, identifying the timing of shift to passive management (shoreline retreat) and exploring factors that influence this potential shift. (PDF contains 4 pages)

Reforming state-level coastal management and development policies: strategic retreat as an innovative, proactive and equitable coastal environmental management strategy

Atlantic and Gulf Coast shorelines include some of the most unique and biologically rich ecosystems in the United States that provide immeasurable aesthetic, habitat and economic benefits. Natural coastal ecosystems, however, are under increasing threat from rampant and irresponsible growth and development. Once a boon to local economies, complex natural forces – enhanced by global climate change and sea level rise - are now considered hazards and eroding the very foundation upon which coastal development is based. For nearly a century, beach restoration and erosion control structures have been used to artificially stabilize shorelines in an effort to protect structures and infrastructure. Beach restoration, the import and emplacement of sand on an eroding beach, is expensive, unpredictable, inefficient and may result in long-term environmental impacts. The detrimental environmental impacts of erosion control structures such as sea walls, groins, bulkheads and revetments include sediment deficits, accelerated erosion and beach loss. These and other traditional responses to coastal erosion and storm impacts- along with archaic federal and state policies, subsidies and development incentives - are costly, encourage risky development, artificially increase property values of high-risk or environmentally sensitive properties, reduce the post-storm resilience of shorelines, damage coastal ecosystems and are becoming increasingly unsustainable. Although communities, coastal managers and property owners face increasingly complex and difficult challenges, there is an emerging public, social and political awareness that, without meaningful policy reforms, coastal ecosystems and economies are in jeopardy. Strategic retreat is a sustainable, interdisciplinary management strategy that supports the proactive, planned removal of vulnerable coastal development; reduces risk; increases shoreline resiliency and ensures long term protection of coastal systems. Public policies and management strategies that can overcome common economic misperceptions and promote the removal of vulnerable development will provide state and local policy makers and coastal managers with an effective management tool that concomitantly addresses the economic, environmental, legal and political issues along developed shorelines. (PDF contains 4 pages)

The island of Kauai, Hawaii's progressive shoreline setback and coastal protection ordinance

Approximately two-thirds of coastal and Great Lakes states have some type of shoreline construction setback or construction control line requiring development to be a certain distance from the shoreline or other coastal feature (OCRM, 2008). Nineteen of 30 coastal states currently use erosion rates for new construction close to the shoreline. Seven states established setback distances based on expected years from the shoreline: the remainder specify a fixed setback distance (Heinz Report, 2000). Following public hearings by the County of Kauai Planning Commission and Kauai County Council, the ‘Shoreline Setback and Coastal Protection Ordinance’ was signed by the Mayor of Kauai on January 25, 2008. After a year of experience implementing this progressive, balanced shoreline setback ordinance several amendments were recently incorporated into the Ordinance (#887; Bill #2319 Draft 3). The Kauai Planning Department is presently drafting several more amendments to improve the effectiveness of the Ordinance. The intent of shoreline setbacks is to establish a buffer zone to protect shorefront development from loss due to coastal erosion - for a period of time; to provide protection from storm waves; to allow the natural dynamic cycles of erosion and accretion of beaches and dunes to occur; to maintain beach and dune habitat; and, to maintain lateral beach access and open space for the enjoyment of the natural shoreline environment. In addition, a primary goal of the Kauai setback ordinance is to avoid armoring or hardening of the shore which along eroding coasts has been documented to ultimately eliminate the fronting beach. (PDF contains 4 pages)

Encouraging sustainable development in a coastal community: New Hanover County, North Carolina's exceptional design zoning district

While New Hanover County is the second smallest county in North Carolina, it is also the second most densely populated with approximately 850 people per square mile. Nestled between the Cape Fear River and Atlantic Ocean with surrounding barrier island beach communities, the County’s geographic location provides a prime vacation destination, as well as an ideal location for residents who wish to live at the water’s edge. Wilmington is the largest city in the County with a population just under 200,000. Most of the Wilmington metropolitan area is developed, creating intense development pressures for the remaining undeveloped land in the unincorporated County. In order to provide development opportunities for mixed use or high density projects within unincorporated New Hanover County where appropriate urban features are in place to support such projects without the negative effects of urban sprawl, County Planning Staff recently developed an Exceptional Design Zoning District (EDZD). Largely based on the LEED for Neighborhood Development program, the EDZD standards were scaled to fit the unique conditions of the County with the goal of encouraging sustainable development while providing density incentives to entice the use of the voluntary district. The incentive for the voluntary zoning district is increased density in areas where the density may not be allowed under normal circumstances. The rationale behind allowing for higher density projects is that development can be concentrated in areas where appropriate urban features are in place to support such projects, and the tendency toward urban sprawl can be minimized. With water quality being of high importance, it is perceived that higher density development will better protect water quality then lower density projects. (PDF contains 4 pages)

Long Bay hypoxia study: A collaborative and multidisciplinary approach

The nearshore waters along the Myrtle Beach area are oceanographically referred to as Long Bay. Long Bay is the last in a series of semi-circular indentations located along the South Atlantic seaboard. The Bay extends for approximately 150 km from the Cape Fear River in North Carolina to Winyah Bay in South Carolina and has a number of small inlets (Figure 1). This region of the S.C. coast, commonly referred to as the “Grand Strand,” has a significant tourism base that accounts for a substantial portion of the South Carolina economy (i.e., 40% of the state’s total in 2002) (TIAA 2003). In 2004, the Grand Strand had an estimated 13.2 million visitors of which 90% went to the beach (MBCC 2006). In addition, Long Bay supports a shore-based hook and line fishery comprised of anglers fishing from recreational fishing piers, the beach, and small recreational boats just offshore. (PDF contains 4 pages)