Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science
Influences of Artificial Reefs on Juvenile Red Snapper along the Mississippi Gulf Coast
This article was found in the Marine and Coastal Fisheries: Dynamics, Management, an Ecosystem on the Fisheries.org website. According to Brandt and Jackson,” artificial reefs have been constructed and placed in the northern Gulf of Mexico to provide structure for a wide range of reef-associated fish species and to further management goals, such as the enhancement of recreational and commercial fishing and the rehabilitation of depleted fish stock.” Artificial reefs might have an effect on the environment they inhibit but these are still on debate. These artificial reefs are said to be found off the Mississippi coast and range along the coast of Alabama. Along these coast their is species of Lutjanus campechanus, also known as the Red Snapper. The Red Snapper uses the artificial reefs for shelter and for finding food. Since Red Snappers are predatory fish and can live up to 50 years of life they have been on the decline over the past years. Since then they have made little improvements and this includes improvement in the survival of Red Snapper juveniles.
The study area that they used was a location about 40 miles from Pascagoula, Ms. This was known as artificial reef haven 13 (FH-13). FH-13 was split into 3 sections, section A, section B and section C. Each section was different in depth but they all had the same structure which was a sandy and muddy bottom. Soon as they were marked within sections the artificial reefs were then placed in a pyramid position. Brandt and Jackson state,” the findings of the this are significant and promising, as few studies have looked at the importance of independent reef unit spacing as it pertains to the relative abundance and length of reef associated juvenile Red Snapper.” Artificial reefs were concluded that they give Red Snappers a offering of fitness benefits, such as shelter for protection and from predators.
Image from www.mexfish.com
Estimating recreational harvest using interview-based recall survey: Implication of recalling in weight or numbers
Fisheries Management and Ecology
May 2, 2013
In this article they talk about how overfishing is affecting the marine environment and how recreational fishing has continued even though recovery has implemented and commercial landings has been regulated. It is estimated that a recreational catch, harvest or effort in several countries was an interview based survey. This consisted on fishers being contacted by email or by phone. They asked questions concerning catches, harvesting and fishing patterns over a period of time. Sparrevohn states,” a recall survey is a method that has been used for decades but mainly focuses on anglers.” Based upon the recall survey it is said that fishers prefer to recall their harvest and what type of fish species they caught. After answering these questions they were asked to answer how they caught their fish.
The methods that were used in this experiment had a two phase recall survey. First survey which was also known as phase 1, were fishers who had received their fishing permit by July 1, 2010. Second phase fishers were those who received their permits by January 1, 2011. In each phase you had over 2400 anglers and 2400 passive gear fishers who were all contacted by email. To separate these two groups anglers had an Angular license were known as Angling A and those with passive gear license were known as Angling B. Over a period of time these fishers were contacted either by email or phone and asked a series of questions pertaining to the fish they caught. Weight, length and species were questions that were asked by the questioner. From here they could determine how many species were caught, the length of each species caught and the weight of each species.
The results were that 80 percent of the initial 9716 were contacted. Only 3 percent of 9,716 did not want to participate In the survey. The remaining percent were not responding due to an incorrect email address or phone number. Out of 46 percent of all the people who were surveyed used the internet to fill out their questioners. Sparrevohn states,” the number of respondents who preferred to report their harvest numbers did so mainly by species harvested and to a lesser extent by fishing methods.”
A Review of fisheries management past and present and some future perspectives for the third millennium
J.F. Caddy, K.L. Cochrane
Ocean Coastal Management 44(2001)
Since the last century the biggest debate for fisheries was that they had no boundaries for fish resources in the ocean. Sine the turn of the century we have made progress within our fisheries. Fisheries management has become more sustainable by using concepts like biology, economics and social and institutional issues that this has made it more intensive then is was ten years ago. Caddy and Cochrane state that” over the past 100 years, despite undeniable progress in our ability to monitor and assess the state of fish stocks and understand the economic and social forces that underlie ecosystem change, the status of fishery resources has deteriorated.”
Early fishery management in the 1900’s was that they encountered many difficult problems of natural resources management and the rapid technological advances. These problems have made today a big issue in resolving them. One example of early fishery regulations was the total allowable catch (TAC), this was based on a scientific data concept from the 1960’s. This was based on bag limits and this system was long gone before it started. It wasn’t a good way to determine in good data.
A history of advances in fishery management, fishery control measures and assessment. According to Caddy and Cochran fisheries assessment was used to determine the life and ecosystems of fish. They use different techniques and to help in their assessments with fish like GIS. “Fishery management is a control of fishing effort as a basic tool for fisheries management and fisheries theory tends to treat fishing effort as a continuous variable that can be controlled indirectly through quotas or even by controls on fleet tonnage or vessels and gear characteristics”, states Caddy and Cochrane. Another technique is monitoring, control and surveillance (MCS).
Caddy and Cochrane state, “despite the emphasis in recent literature on fishery management by input or output control, a modern suite of technical measures will play a key role in making these key control measures effective.” This a perspective on fisheries management measures in the third millennium. Changes have been occurring slowly and making fisheries more selectable and less destructive. The use of square meshes and turtle excluder devices to reduce unwanted catches.
Marine and Coastal fisheries Journal
Impacts of Interannual Environmental Forcing and Climate Change on the Distribution of Atlantic Mackerel on the U.S. Northeast Continental Shelf
W.J. Overholtz, J.A. Hare and C.M. Keith
June 25, 2011
In this journal W.J. Overholtz, J.A. Hare and C.M. Keith are doing research on the climate change in the Atlantic Coast. They are researching the Mackerel fish stock also known as Scomber scombrus. This stock of Mackerel are found between Cape Hatteras to Newfoundland. The Mackerel migrate long distances and they are very sensitive to temperature and the water must be warmer the 5 degrees Celsius. Over the past forty years the Mackerels were being studied and data was being collected using GIS, satellite imagery and research trawls surveys. One thing they have found out is that the Mackerel have shifted from about 250 km to the north and to the east. They also found that the Mackerel have moved from deeper waters to the more shallower waters. This would be due to the waters warming up and making migration patterns more difficult to use. The climate has also changed the food patterns they ate over the years. One important change was the spawning season for the Mackerel. You could see a decline in the number of Mackerels that spawned over the past 40 years. This has caused great changes in commercial fisheries along with recreational fisheries. They believe that this would make it harder to fish and catch the Mackerel in the future.
Image of Northeast Atlantic Mackerel. www.fisherieswiki.org
Image of Alewife herring. Photo by: cornell.edu
Image of Blueback Herring. Photo by: cornell.edu
Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science
Volume 4, Issue 1, 2012
Kevin Magowan, Joshua Reitsma and Diane Murphy
In this Journal Kevin Magowan, Joshua Reitsma and Diane Murphy were trying to assess their ability to use dual-frequency identification sonar (DIDSON) to capture migrating alewife, Alosa pseudoharengus and blueback, Alosa aestivalis. They did this research on the coast of Massachusetts. Two sites were used in this study to show how migrating herring were adapting to their environment. Herring River and the second location was located above a control dam at the outlet of Hinckley’s Pond. The crew processed each data using different techniques. One technique for using the DIDSON was using a software to determine how many migrating herring were swimming up the rivers. This one technique had multiple steps on using the DIDSON. One step was tally counting which involved manually counting the herring as they swam by the DIDSON. The second step was mark and measure. This step required the person to use the DIDSON software to count each fish in different time frames. Playback was important to reading how each fish was traveling and what type of species of herring was swimming up the river. The last step was using autocount. In autocount every fish was automatically counted regardless of the direction and species. This function was limited to good data because they were unable to discern species and direction of travel.
The data that they collected from site one which was at Herring River was processed using the fast-replay tally counting step. This took them 19.5 hours to look over and they concluded that out of 4,312 fish 4,134 were classified as the river herring. Using the mark and measure step it took them 33 hours to count. Out of those 33 hours of counting they figured 4,310 fish that passed the DIDSON only 4,119 were classified at the river herring. The autocount step took only 11 hours to process. They had over 2,300 river herring. The data collected at site 2 which was at Hinckley’s Pond. This was processed by a single observer using only fast replay tally counting and the mark and measure steps. The total number of fish spotted was only 1. Magowan et al states.” DIDSON is an effective type of sonar with which to count river herring in a small coastal stream, as is evident by the many clear images of river herring that they we collected during the day and at night”.