Improvements to Data Collection in Commercial Fisheries Using Electronic Reporting Methods: Cost/Efficiency and Implications for Use in Ecosystem Management.

Data have been collected on fisheries catch and effort trends since the latter half of the 1800s. With current trends in declining stocks and stricter management regimes, data need to be collected and analyzed over shorter periods and at finer spatial resolution than in the past. New methods of electronic reporting may reduce the lag time in data collection and provide more accurate spatial resolution. In this study I evaluated the differences between fish dealer and vessel reporting systems for federal fisheries in the US New England and Mid-Atlantic areas. Using data on landing date, report date, gear used, port landed, number of hauls, number of fish sampled and species quotas from available catch and effort records I compared dealer and vessel electronically collected data against paper collected dealer and vessel data to determine if electronically collected data are timelier and more accurate. To determine if vessel or dealer electronic reporting is more useful for management, I determined differences in timeliness and accuracy between vessel and dealer electronic reports. I also compared the cost and efficiency of these new methods with less technology intensive reporting methods using available cost data and surveys of seafood dealers for cost information. Using this information I identified potentially unnecessary duplication of effort and identified applications in ecosystem-based fisheries management. This information can be used to guide the decisions of fisheries managers in the United States and other countries that are attempting to identify appropriate fisheries reporting methods for the management regimes under consideration. (PDF contains 370 pages)

U.S. Caribbean fish trap fishery costs and earnings study

Executive Summary: This study describes the socio-economic characteristics of the U.S. Caribbean trap fishery that encompasses the Commonwealth of Puerto Rico and Territory of the U.S. Virgin Islands. In-person interviews were administered to one hundred randomly selected trap fishermen, constituting nearly 25% of the estimated population. The sample was stratified by geographic area and trap tier. The number of traps owned or fished to qualify for a given tier varied by island. In Puerto Rico, tier I consisted of fishermen who had between 1-40 fish traps, tier II was made up of fishermen who possessed between 41 and 100 fish traps, and tier III consisted of fishermen who held in excess of 100 fish traps. In St. Thomas and St. John, tier I was composed of fishermen who held between 1 and 50 fish traps, tier II consisted of fishermen who had between 51-150 fish traps and tier III was made up of fishermen who had in excess of 150 fish traps. Lastly, in St. Croix, tier I was made up of fishermen who had less than 20 fish traps and tier II consisted of fishermen who had 20 or more fish traps. The survey elicited information on household demographics, annual catch and revenue, trap usage, capital investment on vessels and equipment, fixed and variable costs, behavioral response to a hypothetical trap reduction program and the spatial distribution of traps. The study found that 79% of the sampled population was 40 years or older. The typical Crucian trap fisherman was older than their Puerto Rican and St. Thomian and St. Johnian counterparts. Crucian fishermen’s average age was 57 years whereas Puerto Rican fishermen’s average age was 51 years, and St. Thomian and St. Johnian fishermen’s average age was 48 years. As a group, St. Thomian and St. Johnian fishermen had 25 years of fishing experience, and Puerto Rican and Crucian fishermen had 30, and 29 years, respectively. Overall, 90% of the households had at least one dependent. The average number of dependents across islands was even, ranging between 2.8 in the district of St. Thomas and St. John and 3.4 in the district of St. Croix. The percentage utilization of catch for personal or family use was relatively low. Regionally, percentage use of catch for personal or family uses ranged from 2.5% in St. Croix to 3.8% in the St. Thomas and St. John. About 47% of the respondents had a high school degree. The majority of the respondents were highly dependent on commercial fishing for their household income. In St. Croix, commercial fishing made up 83% of the fishermen’s total household income, whereas in St. Thomas and St. John and Puerto Rico it contributed 74% and 68%, respectively. The contribution of fish traps to commercial fishing income ranged from 51% in the lowest trap tier in St. Thomas and St. John to 99% in the highest trap tier in St. Croix. On an island basis, the contribution of fish traps to fishing income was 75% in St. Croix, 61% in St. Thomas and St. John, and 59% in Puerto Rico. The value of fully rigged vessels ranged from $400 to $250,000. Over half of the fleet was worth $10,000 or less. The St. Thomas and St. John fleet reported the highest mean value, averaging $58,518. The Crucian and Puerto Rican fleets were considerably less valuable, averaging $19,831 and $8,652, respectively. The length of the vessels ranged from 14 to 40 feet. Fifty-nine percent of the sampled vessels were at least 23 feet in length. The average length of the St. Thomas and St. John fleet was 28 feet, whereas the fleets based in St. Croix and Puerto Rico averaged 21 feet. The engine’s propulsion ranged from 8 to 400 horsepower (hp). The mean engine power was 208 hp in St. Thomas and St. John, 108 hp in St. Croix, and 77 hp in Puerto Rico. Mechanical trap haulers and depth recorders were the most commonly used on-board equipment. About 55% of the sampled population reported owning mechanical trap haulers. In St. Thomas and St. John, 100% of the respondents had trap haulers compared to 52% in Puerto Rico and 20% in St. Croix. Forty-seven percent of the fishermen surveyed stated having depth recorders. Depth recorders were most common in the St. Thomas and St. John fleet (80%) and least common in the Puerto Rican fleet (37%). The limited presence of emergency position indication radio beacons (EPIRBS) and radar was the norm among the fish trap fleet. Only 8% of the respondents had EPIRBS and only 1% had radar. Interviewees stated that they fished between 1 and 350 fish traps. Puerto Rican respondents fished on average 39 fish traps, in contrast to St. Thomian and St. Johnian and Crucian respondents, who fished 94 and 27 fish traps, respectively. On average, Puerto Rican respondents fished 11 lobster traps, and St. Thomian and St. Johnian respondents fished 46 lobster traps. None of the Crucian respondents fished lobster traps. The number of fish traps built or purchased ranged between 0 and 175, and the number of lobster traps built or bought ranged between 0 and 200. Puerto Rican fishermen on average built or purchased 30 fish traps and 14 lobster traps, and St. Thomian and St. Johnian fishermen built or bought 30 fish traps and 11 lobster traps. Crucian fishermen built or bought 25 fish traps and no lobster traps. As a group, fish trap average life ranged between 1.3 and 5 years, and lobster traps lasted slightly longer, between 1.5 and 6 years. The study found that the chevron or arrowhead style was the most common trap design. Puerto Rican fishermen owned an average of 20 arrowhead traps. St. Thomian and St. Johnian and Crucian fishermen owned an average of 44 and 15 arrowhead fish traps, respectively. The second most popular trap design was the square trap style. Puerto Rican fishermen had an average of 9 square traps, whereas St. Thomian and St. Johnian fishermen had 33 traps and Crucian fishermen had 2 traps. Antillean Z (or S) -traps, rectangular and star traps were also used. Although Z (or S) -traps are considered the most productive trap design, fishermen prefer the smaller-sized arrowhead and square traps because they are easier and less expensive to build, and larger numbers of them can be safely deployed. The cost of a fish trap, complete with rope and buoys, varied significantly due to the wide range of construction materials utilized. On average, arrowhead traps commanded $94 in Puerto Rico, $251 in St. Thomas and St. John, and $119 in St. Croix. The number of trips per week ranged between 1 and 6. However, 72% of the respondents mentioned that they took two trips per week. On average, Puerto Rican fishermen took 2.1 trips per week, St. Thomian and St. Johnian fishermen took 1.4 trips per week, and Crucian fishermen took 2.5 trips per week. Most fishing trips started at dawn and finished early in the afternoon. Over 82% of the trips lasted 8 hours or less. On average, Puerto Rican fishermen hauled 27 fish traps per trip whereas St. Thomian and St. Johnian fishermen and Crucian fishermen hauled 68 and 26 fish traps per trip, respectively. The number of traps per string and soak time varied considerably across islands. In St. Croix, 84% of the respondents had a single trap per line, whereas in St. Thomas and St. John only 10% of the respondents had a single trap per line. Approximately, 43% of Puerto Rican fishermen used a single trap line. St. Thomian and St. Johnian fishermen soaked their traps for 6.9 days while Puerto Rican and Crucian fishermen soaked their traps for 5.7 and 3.6 days, respectively. The heterogeneity of the industry was also evidenced by the various economic surpluses generated. The survey illustrated that higher gross revenues did not necessarily translate into higher net revenues. Our analysis also showed that, on average, vessels in the trap fishery were able to cover their cash outlays, resulting in positive vessel income (i.e., financial profits). In Puerto Rico, annual financial profits ranged from $4,760 in the lowest trap tier to $32,467 in the highest tier, whereas in St. Thomas and St. John annual financial profits ranged from $3,744 in the lowest tier to $13,652 in the highest tier. In St. Croix, annual financial profits ranged between $9,229 and $15,781. The survey also showed that economic profits varied significantly across tiers. Economic profits measure residual income after deducting the remuneration required to keep the various factors of production in their existing employment. In Puerto Rico, annual economic profits ranged from ($9,339) in the lowest trap tier to $ 8,711 in the highest trap tier. In St. Thomas and St. John, annual economic profits ranged from ($7,920) in the highest tier to ($18,486) in the second highest tier. In St. Croix, annual economic profits ranged between ($7,453) to $10,674. The presence of positive financial profits and negative economic profits suggests that higher economic returns could be earned from a societal perspective by redirecting some of these scarce capital and human resources elsewhere in the economy. Furthermore, the presence of negative economic earnings is evidence that the fishery is overcapitalized and that steps need to be taken to ensure the long-run economic viability of the industry. The presence of positive financial returns provides managers with a window of opportunity to adopt policies that will strengthen the biological and economic performance of the fishery while minimizing any adverse impacts on local fishing communities. Finally, the document concludes by detailing how the costs and earnings information could be used to develop economic models that evaluate management proposals. (PDF contains 147 pages)

The cost of quinine Cinchona pubescens control on Santa Cruz Island, Galapagos

We analyse the cost of controlling the invasive quinine tree Cinchona pubescens Vahl in the highlands of Santa Cruz Island, Galapagos. Control costs in ten 400 m2 plots formed the basis for estimating the cost of control over the whole island. In the plots, densities were 2100–24,000 stems/ha (stems >150 cm tall) and 55,000–138,000 stems/ha (all size classes combined). Control involved uprooting small plants, and applying of a mix of metsulfuron methyl and picloram to cut stumps or to machete cuts in the bark of larger trees. These methods are presently used by Galapagos National Park field crews to control quinine. Costs (in man hours, herbicide and US$) were related to stem density; the density of stems summed across four height classes was a better predictor of costs than density of any one size class. Regressions (on all size classes combined) formed the basis for predictive models of costs. Costs ranged from $14 to $2225 per ha depending on stem density. The amount of herbicide (active ingredient/ha) that must be applied to high density stands of quinine is higher than typical rates of application in an agricultural setting. The cost of treating all existing plants once across quinine’s known range on Santa Cruz Island (c. 11,000 ha) was estimated at c. US$1.65 million. CDF Contribution Number 1013.

Episodic variations in stream water chemistry associated with acid rainfall and run-off and the effect on aquatic ecosystem, with particular reference to fish populations in N.W. England

This is the episodic variations in stream water chemistry associated with acid rainfall and run-off and the effect on aquatic ecosystems, with particular reference to fish populations in North West England produced by the North West Water Authority in 1985. This report looks at the biological, physical and chemical information collected over a five year period from over 100 sites on upland streams in the North West Region of which drained rocks of low buffering capacity. In both Lake District and South Pennine sites striking differences were found between the composition of invertebrate communities inhabiting acid-stressed and less acid-stressed streams. Electric fishing surveys showed that acidic streams (geometric mean pH <5.5) generally had abnormally low densities of salmonids ( < 0 .2m2) and that 0+ fish were very few or absent. The latter indicates recruitment failure. Salmon were more sensitive than trout to low pH.

Development of low cost feed using local ingredients for culture of freshwater prawn, Macrobrachium rosenbergii in ponds

Two experiments were conducted to formulate and evaluate test diets using locally available ingredients to find out suitable diets for mono and polyculture of Macrobrachium rosenbergii in ponds. The first experiment was conducted from 1 July 2003 to 29 September 2003 in 12 experimental ponds each measuring 30 square meters behind the Fisheries Faculty Building, BAU campus, Mymensingh. Three experimental diets containing 30% protein were formulated using fish meal, meat and bone meal, mustard oilcake, sesame meal and rice bran and assigned to treatments 1, 2 and 3, respectively. A special shrimp feed (Starter-II) from Saudi-Bangla Fish Feed Ltd. was assigned to treatment 4 (Control). Each treatment had three replications. Juveniles of M. rosenbergii (2.90±0.81g) were stocked at the rate of 4/square meter. Prawns were fed three times daily at the rate of 15% of their body weight at the beginning, which was gradually reduced to 10% and 5% for the last two months. There was no significant (P>0.05) difference between the weight gains of prawns fed diets 1 and 4 (control), but they were significantly (P<0.05) higher than those of diets 2 and 3. The FCR values of diets ranged between 2.61 to 3.36 with diets 1 and 4 showing significantly (P<0.05) lower FCR values. The survival rate of prawns ranged between 68 to 78% with prawns fed diets 1 and 4 showing significantly higher survival rate. The production of prawn ranged from 921 to 1,428 kg/ha/90 days and diet 1 gave the highest production. Treatment 1 gave the highest net profit ofTk. 161,980/ha/90 days. The second experiment was conducted from December, 2003 to April, 2004 to see the growth of over wintered M. rosenbergii juveniles in polyculture with indigenous major carps (catla and rohu) in ponds using formulated diets. Three isoenergetic experimental diets formulated using fish meal, meat and bone meal, mustard oil cake, rice bran, wheat bran and molasses, and a shrimp feed 'Golda special feed' from Saudi-Bangla Fish Feed Ltd. were assigned to treatments 1, 2, 3 and 4 (control), respectively, each treatment had two replications. Eight experimental ponds each measuring 80 square meters in the Field Laboratory Complex of the Faculty of Fisheries, BAU campus, Mymensingh were used. The mean initial weights of M. rosenbergii, catla and rohu were 1.60±0.01, 30.0±0.09 and 25.0±0.08 g, respectively. A total of 160 fish and prawn (20,000/ha) were stocked in each pond at the ratio of 2:1:1 (prawn: catla: rohu). Fish were fed at the rate of 3-5% of their body weight. Prawns fed diet 1, 2 and 4 showed higher weight gains compared to diet 3. The weight gain of catla was significantly higher in T1 while in case of rohu was higher in T1 and T4, respectively. There were no significant differences (P>0.05) in the survival rate of fish as obtained from different treatments. The overall total fish production ranged from 2196 to 2679 kg/ha/5 months. The highest production and the highest profit (Tk. 56,531/ha/5 months) was obtained from T1 and the lowest (Tk. 24,932/ha/5 months) from T4.

Production of freshwater giant prawn using over-wintered juveniles for enhancement of farm income and reduction of rural poverty in Bangladesh

Freshwater giant prawn, Macrobrachium rosenbergii fry produced during late season can not withstand low temperature thus the prawn culture programme during winter is hampered. To overcome this problem, late season (August-September) prawn juveniles (0.9-6.8 g) were stocked at a density of 1.43 to 3.57/square meter in 350-476 square-meter ponds in Pabna and Mymensingh districts during October 2000 and cultured till May 2001. Monthly average water temperature during the winter months (December-February) varied from 16 to 22 °C and gradually increased to 32 °C in May. The prawn fry showed fast growth rate and attained an average weight of 60-70 g within eight months including three winter months. Growth compensation was observed during summer months. Survival rate was 60-79%. After extrapolation of the present growth rate more than 1,600 kg/ha production can be achieved in better-managed ponds. Extrapolated cost of production was Tk. 268,000 and 200,000 Tk./ha in two best ponds, sale value was Tk. 644,9146 [sic] and 528,466 and gross profit was Tk. 376,000-410,000, suggesting a higher economic feasibility of farming freshwater prawn with over-wintered juveniles.