Month: July 2016
Water Quality Analysis of Antipoison Creek
We have been collecting water quality data on Antipoison Creek for about 11 months now, sampling for nitrate-nitrites (NO23), phosphates (PO4), ammonium (NH4), and chlorophyll. Our data collection extends from last September to this May (with sampling ongoing). Last month, Gary, Libby and I visited with Dr. Lora Harris, an associate professor at the University of Maryland’s Center for Environmental Science (UMCES), who specializes in systems ecology and ecosystem modeling, to get input on how to analyze our water quality data.
Dr. Harris gave us several suggestions, one of which was to create a Nitrogen Loading Model (NLM) for Antipoison Creek, to determine if the creek is primarily fed by nitrogen coming in from the Chesapeake Bay, or from the watershed (land-based activity and runoff, groundwater leaching, and atmospheric deposition). Harris described the NLM as a type of box model, showing inputs and outputs in and from a watershed. (See Figure 1, from the NLM instruction manual below).
The Nitrogen Loading Model, created by Mark J. Brush (VIMS), Lora A. Harris (UMCES), Juliette C. Giordano (VIMS), and Joanna K. York (UDEL) allows a user to put in data on land use and activity in a specific watershed- for us, Antipoison Creek. The model pulls in miscellaneous information on the watershed, such as atmospheric deposition, loads from point sources, and surface area of the creek. It also pulls in data on non-agricultural and agricultural land cover, as well as the fertilization rate and agricultural yield of each crop grown in the watershed.
Using a mix of applications including a GIS operating system (QGIS) and GoogleEarth, as well as a number of sources on Antipoison Creek and Lancaster County, we came up with estimates for the needed parameters. Once all the inputs were entered, and the model generated kilograms of nitrogen for groundwater input, wastewater input, direct atmospheric deposition onto water surface, and a total annual load of nitrogen (kg) entering the watershed, we contacted Dr. Brush to discuss our procedure and results.
Now that we have an annual watershed load for nitrogen to the estuary, we must determine if Antipoison Creek has a greater flux of nitrogen coming from the watershed and emptying out into the Bay, or if the Bay is primarily feeding the creek with an influx of nitrogen.
We will be working with Dr. Brush on this next step, as well as a more in-depth paper to share our work on the NLM model.
Source: Brush, M.J., L.A. Harris, J.C.P. Giordano, and J.K. York. 2015. Delmarva Coastal Bays Nitrogen Loading Model. Virginia Institute of Marine Science, Gloucester Point, VA. Available at: http://www.vims.edu/research/departments/bio/programs/semp/models/index.php.
The Impact of Catch Share Programs on Chesapeake Fish Landings
Last week, Libby introduced catch share programs, shared their pros and cons, and briefly outlined existing programs in the Chesapeake Bay region. As a continuation of her previous report, using data from NOAA and the Environmental Defense Fund, she graphed Virginia and Maryland fish landings for several species over a ten-to-twelve-year period. The data for these fish- striped bass, black sea bass, and summer flounder- shows numbers for fish landings both five-to-six years before a catch share program was implemented in each state for each species, and the five years following.
In her former piece, Libby stated that populations of striped bass in the Chesapeake had risen since catch share programs were implemented in Virginia and Maryland. Our first graph for striped bass landings in Virginia (1992 -2004) seems to correlate. Since catch share programs for striped bass were implemented in the Chesapeake region in 1998, both populations and fish landings (in metric tons) for striped bass have increased.
Catch sharing was implemented in Maryland for summer flounder in 2005. The immediate year after implementation, landings decreased, but for the next four years, landings followed an upward trend. It would seem that the catch share program has had a positive impact on harvests for the summer flounder.
Catch share programs do not seem to be having a positive effect on all Chesapeake finfish species, however – at least in terms of harvest numbers. Fish landings for black sea bass (1998-2010) decreased in both Virginia and Maryland after catch share programs were implemented in both states in 2004. It is difficult to tell if catch sharing has been a significant cause for this decline. Landings were decreasing prior to 2004, and continued to do so afterwards. It could be that a combination of factors contributed to a decline in black sea bass landings.
Catch Shares in the Chesapeake Bay and Beyond
By Libby Warner
On our visit to Antipoison Creek, we met with a fisherman who spoke somewhat highly of catch share programs. Afterwards, I investigated the purpose of catch share programs as well as the pros and cons of their implementation.
Catch share programs were originally developed in the United States to promote the economic and environmental stability of fisheries. In 1976, the federal government officially acknowledged that overfishing was a national issue and passed the Magnuson Steven’s Act. This created regional councils to manage fishing practices in different parts of the country. The act was first amended in 1996 with the Sustainable Fisheries Act. This amendment limited fisheries to only fishing during certain times of the year, a method referred to as derby fishing. Fishermen would fish as much as they could during the limited time frame, which resulted in increases in overfishing, illegal poaching, and competition and conflict between recreational and commercial fishermen. There were also several negative economic impacts associated with derby fishing. In 2006, the Magnuson Steven’s Act was amended with the Fishery Conservation and Management Reauthorization Act, which installed various catch share programs throughout the country.
In regions with catch share programs, including the Chesapeake Bay, a total maximum number of allowable catch is instated per annum for a particular species of fish. Individual fishermen and companies are then assigned a TAC, or total allowable catch, a quota based on the number of fish each company caught in the past. Many question the fairness of quotas decided in this fashion. However, the incentive of catch share programs is to limit the amount of fish caught overall rather than limiting the time of year fish can be caught.
In addition to limiting total catch, there are a number of benefits associated with catch share programs. For instance, since the implementation of catch share programs, the Chesapeake Bay, along with other bodies of water throughout the country, have seen a decrease in the number of discards and ghost fish, (fish that get caught in equipment and either die or are lost). There have also been improvements in fishermen safety. During the derby fishing days, fishing was one of the most dangerous jobs in the country. Due to time constraints, fishermen would rush out to catch fish despite poor weather conditions. With the removal of time constraints, catch share programs have provided more full-time jobs, rather than part-time jobs as fishermen now have a year-round season.
Another benefit of catch share fishing is that it increases the quality of fish caught. Since companies own portions of fish stock, they are often more invested in taking care of their stock. Being free to fish any time of year results in fishermen focusing on quality rather than quantity of fish caught. This is especially beneficial for the health of local people who rely on fish as a primary source of protein.
Whether or not catch share programs have actually made fishing more environmentally sustainable is still up for debate. Many argue that proof of success includes rebounds of fish populations across the country, including blue king crab, snow crab, Pacific coast widow rockfish, Atlantic windowpane flounder, and Gulf of Mexico red snapper. While the government has been able to increase total catch limits over time, showing proof of sustainability, many also argue that it is difficult to determine whether or not the rebounds in fish populations are a direct result of catch share programs. Many environmental activists are opposed to catch shares because it is essentially a privatization of public resources. Fishing companies are allowed to trade or sell quota, which results in armchair fishermen, (large fishing companies who sell quota to smaller companies and receive a portion of the profit). Large companies are now more capable of taking over the industry and owning most of the shares. Grassroots environmental activists use the phrase “corporate industrialization of fisheries” to describe the large fishing companies that are becoming monopolies in the fishing world. This is potentially problematic because large corporations in a capitalist society do not always rank environmental interests as a priority. Additionally, although catch share programs have resulted in a shift from part-time jobs to full-time jobs, overall, the monopoly aspect of catch shares has decreased the total number of jobs available.
Catch share programs approach conservation by focusing on individual species of fish rather than looking at aquatic ecosystems as a whole. Many environmental activists argue that the real issue is that, worldwide, there are currently approximately five times as many boats fishing as would be needed to catch a sustainable number of fish. With the implementation of catch share programs, fishermen often respond by simply moving to other parts of the world. Therefore, the total number of fish caught worldwide may not be reduced.
Catch shares are just as controversial in the Chesapeake Bay. Ten years ago, Virginia installed a catch share program in the Bay for striped bass, a population that had been overfished. After the catch share implementation, Virgina has been able to sustainably manage the striped bass population. To implement this program, NOAA provided educational sessions for striped bass fishermen to learn about catch shares and aided fishermen in the transition process from derby fishing to catch share fishing. From an original catch season of three months, the government extended the harvest period for striped bass to eleven months. The Virginia program has also allowed fisheries to be more economically successful.
Another positive result of catch share programs in Virginia is the development of “Chesapeake Catch.” Chesapeake Catch is a smartphone application developed for fishermen in the Bay, allowing them to log their catch and view data regarding other fish caught in the Bay. This has been a successful way for fishermen to come together and communicate within the industry.
Maryland took longer to implement the catch share program for striped bass; a total allowable catch was not instituted until 2014. Catch shares in both Maryland and Virginia have received criticism for putting small fishermen out of business. Throughout the Bay region, many fishermen, particularly smaller family businesses, complain that catch shares have changed their traditional fishing techniques, and allowed larger fishing corporations to control the small companies.
With striped bass being Maryland’s state fish and it’s third most valuable seafood industry, the catch share program implementation for striped bass in Maryland is very significant. Despite the complaints, since the program began, striped bass populations have improved and overfishing has declined in both Maryland and Virginia.
After exploring the different stances people take toward catch shares, and examining the pros and cons of this fishing technique, I have come to the conclusion that overfishing is an extremely complicated issue with no simple solution. It is still relatively unclear whether or not these programs are environmentally sustainable on a global scale. Catch share programs, however, seem to be effective in the Chesapeake Bay watershed. Although there are may be short-term economic downsides to catch shares, there have been ecological benefits in the Chesapeake region.
Osprey on Antipoison Creek
By Gary Greenwood
This past Saturday was a beautiful summer day on Antipoison Creek. As we were sitting outside enjoying the view and breeze, we would occasionally hear a loud splash just off the shore. We would look up just in time to see the osprey surface and try to gain altitude with a fresh-caught fish in his talons. We named him Sam.
There is an osprey nest on a pole not too far from our shore, close to the oyster farm. It’s on a piling, not as high above the water as it should be, but the osprey population is increasing, so they use any suitable platform they can find. Last year it was just a piece of plywood, and in a storm the nest was at risk of blowing away. So in late March my neighbor Glenn and I added some nice 6-inch walls around the edge of the plywood. We had no sooner gotten back to shore than we saw two osprey pairs checking it out. Sam and Louise won out, and proceeded to build a nice nest.
After Sam caught the fish, we could see Louise through the telescope, chattering away. Soon Sam came along with the fish, and two young chicks stuck their heads up for dinner. The feathers are all dark grey, and the necks are long. Louise would pick a piece of meat off the fish and feed it to the chicks. They aren’t ready to fly, but they do a good job eating and sleeping.
I didn’t get any good pictures on Saturday, so the next day, even though it was rainy, I went over and got a nice picture of a very wet Louise watching over her chicks. Unfortunately, the chicks weren’t sticking their heads up unless there was a fish, so you can’t see them in the picture.
The Chesapeake Bay Stock Assessment Committee Releases Annual Advisory Report on Blue Crabs
We’ve seen reports that the blue crab population is up this season, and activity has certainly increased in Antipoison Creek compared to recent years. We have at least three crabbers with pots at the mouth of the creek, collecting bushels of crabs in the double digits many days. We’re about halfway through the crabbing season, which is when the Chesapeake Bay Stock Assessment Committee (CBSAC) releases their advisory report each summer on blue crabs. Made up of state agencies and scientists from Maryland and Virginia, the most recent publication, issued June 30, echoes other recent reports we’ve read about crab population abundance.
One thing the CBSAC highlights is the abundance of female crabs in the Bay (which gives an indication of how the overall population will look in the next year). The committee keeps track of population estimates for adult female crabs, juvenile crabs, and male crabs in the Bay. The committee also sets threshold limits and targets for adult female population numbers. The threshold limit, the point at which the adult female population should not fall below, is set at 70 million; the target is set at 215 million.
This year at the beginning of the harvest season, the committee counted an estimated 194 million spawning age female crabs, which is a 92% rise from last spring’s count. Because only 15% of adult females were harvested last year, which was below the 25.5% harvest target, and given that 194 million adult females is well above the 70 million threshold, the Stock Assessment Committee has declared that overfishing is not occurring in the Bay.
However, the count of adult females is still something to look out for, regardless of how well the population is doing this year, especially as the current season continues. The CBSAC points out that it was only two years ago when the adult female crab population dropped below the 70 million-threshold mark. Blue crab population numbers can be extremely variable, so a good harvest and population one year does not ensure healthy numbers for the next season.
The CBSAC report includes a list of recommendations to continue to support and increase the blue crab population, which includes expanding blue crab sanctuaries in Virginia (Lower Bay), Maryland (Upper Bay), and parts of the Potomac River (overseen by the Potomac River Fisheries Commission) to protect females of spawning age. The CBSAC also calls for improvements in surveys and data acquisition needed to make more informed estimates of current population numbers. One other recommendation made by the commission, dependent on further assessment, is instating an annual total allowable catch (TAC), which is a fisheries method we will go into more detail on here shortly.
You can check out the full CBSAC 2016 report here.