The Effects Of A Regulatory Gear Restriction On The Recruiting Year Class In The Sea Scallop, Placopecten Magellanicus (Gmelin, 1791), Fishery

In 1994, Amendment 4 to the sea scallop (Placopecten magellanicus) fishery management plan was adopted, which restricted fishing effort by controlling vessel days at sea. crew size, and gear size. Dredge ring size was increased from 76.2 mm (3.0 ) to 82.6 mm (3.25 ) in March 1994, and again to 88.9 mm (3.5 ) in January 1996 to increase the age of entry of scallops into the fishery. Between June 1994 and April 1995, four trips were taken on commercial scallop vessels in the western mid-Atlantic to determine harvest efficiency of 88.9-mm dredge rings relative to 82.6-mm dredge rings used in the fishery at the time. Our study focused on the abundant and nearly ubiquitous 3-year-old, 1990 year class. At the time, individuals in this year class were approaching the size (70 mm) of both full recruitment to the gear and recruitment into the fishery. Relative harvest efficiency of this year class ranged from 60% to 72% over the study period. The 88.9-mm rings were found to be 90% efficient when scallops had grown to a size of 100-105 mm. The 88.9-mm ring dredge would therefore delay full recruitment of the 1990 year class for almost 1 y relative to the 82.6-mm ring dredge. Analysis shows that this delay could increase yield-per-recruit by almost 10% and spawning stock biomass by 40% to 60%,. Benefits of the gear modifications will only be fully realized when used in conjunction with other measures that reduce or stabilize fishing effort

A general equilibrium model for Atlantic herring (Clupea harengus) with ecosystem considerations

A framework is presented for assessing the economic ramifications of ecosystem-based management decisions, with attention focused on Atlantic herring (Clupea harengus) in New England. The Atlantic herring has often been referred to as the most important fish in the northeastern United States because it is a filter-feeder, is believed to improve water quality, and is very important to the health, growth, and abundance of major gamefish, marine mammals, seabirds, and several species of fish. Although many approaches for examining the potential economic ramifications of ecosystem-based management are possible, attention is focused on one method that can be used given existing data. A static, deterministic input/output (I/O) optimization (IOLP, input/output linear programming) model is developed that breaks out the impact of different decisions on herring allocation on the 2006 New England regional economy of Maine, New Hampshire, Massachusetts, and Rhode Island. The IOLP model is a promising approach for informing policy-makers of the economic implications of various allocation choices. The framework is also flexible enough to allow further disaggregation of the small model presented to include additional fishing and non-fishing sectors

A Comparison Of Size Selectivity And Relative Efficiency Of Sea Scallop, Placopecten Magellanicus (Gmelin, 1791), Trawls And Dredges

During August and September 1997 and May 1998, three comparative fishing experiments were conducted aboard commercial sea scallop trawl and dredge vessels to assess the efficacy of gear restrictions found in Amendment 3 to the Sea Scallop Fishery Management plan (SSFMP). This amendment involved certain gear restrictions including minimum mesh and ring sizes and maximum Scar widths and was intended to equate the performance of sea scallop trawls and dredges with respect to size selectivity and efficiency. Statistical analysis indicated that selectivity and efficiency were not equal for the two gear types. while absolute gear size selectivity could not be estimated, there was clear evidence of differential relative size selectivity between the two gears. Relative harvest efficiency values shifted at 90 to 95 mm shell height. Trawl vessels were more efficient capturing sea scallops less than 90 mm, and dredge vessels were more efficient capturing sea scallops greater than 90 tnm. This shift in relative harvest efficiency coupled with an observed cull size at 70 to 75 mm shell height resulted in the bawl vessels being more dependent on age 3 sea scallops with shell heights of 70 to 90 mm. Operational differences observed between the two gear types restricted sea scallop trawl vessels to areas of smooth substrate. Large differences in both relative efficiencies and operational requirements will present considerable impediments to the desired outcomes of having equivalent performance between gear types

Incentive-based approaches to sustainable fisheries

The failures of traditional target-species management have led many to propose an ecosystem approach to fisheries to promote sustainability. The ecosystem approach is necessary, especially to account for fishery-ecosystem interactions, but by itself is not sufficient to address two important factors contributing to unsustainable fisheries: inappropriate incentives bearing on fishers and the ineffective governance that frequently exists in commercial, developed fisheries managed primarily by total-harvest limits and input controls. We contend that much greater emphasis must be placed on fisher motivation when managing fisheries. Using evidence from more than a dozen natural experiments in commercial fisheries, we argue that incentive-based approaches that better specify community and individual harvest or territorial rights and price ecosystem services and that are coupled with public research, monitoring, and effective oversight promote sustainable fisheries

US Caribbean fish trap fishery socioeconomic study

Concerns over the potential impacts of trap fishing on coral reefs and associated habitats prompted a socioeconomic study to characterize the U.S. Caribbean fish trap fishery in anticipation of management actions. Stratified random interviews of one hundred fishermen revealed the presence of a diverse fishery, with appreciable inter-island differences in levels of fishing dependence, fishing practices, and capital investment. High levels of fishing dependence Were observed among fishermen in the U.S. Virgin Islands, whereas Puerto Rican fishermen exhibited a more diversified livelihood strategy. Fishermen from St. Croix derived 62% of their household income from fish traps, significantly more than fishermen from St. Thomas/St. John and Puerto Rico, who derived 45% and 41%, respectively, of their household incomes from fish traps. The St. Thomas/St. John fleet was also larger and more capital-intensive than the Crucian and Puerto Rican fleets. This structural heterogeneity suggests that fishermen from the various islands may respond differently to the same regulatory constraint. Thus, targeted policies may be necessary to improve the socioeconomic performance of the fishery and the political acceptability of management actions

Cross-sectional and longitudinal construct validity of two rotator cuff disease-specific outcome measures

BACKGROUND: Disease-specific Quality Of Life (QOL) measures are devised to assess the impact of a specific disease across a spectrum of important domains of life. The purpose of this study was to examine the cross-sectional and longitudinal construct validity (sensitivity to change) of two rotator cuff disease-specific measures, the Rotator Cuff-Quality Of Life (RC-QOL) and the Western Ontario Rotator Cuff (WORC) index, in relation to one another and to other joint and limb specific measures in the same population of the patients suffering from rotator cuff pathology. METHODS: Participants enrolled were consecutive patients who received physical therapy for management of impingement syndrome or received treatment following rotator cuff repair, acromioplasty or decompression surgeries. All subjects received physical therapy treatment and completed four outcome measures at 3 single points (initial, interim, and final). Cross-sectional convergent validity was assessed at each of the 3 time-points by correlating the WORC and RC-QOL's scores to each other and to two alternative scales; a joint-specific scale, the American Shoulder and Elbow Surgeons (ASES) standardized shoulder assessment form and a limb-specific measure, the Upper Extremity Functional Index (UEFI). Non-parametric statistics (Spearman's rho and Wilcoxon-Mann-Whitney tests) examined the construct validity. The standardized response mean (SRM) was used to examine sensitivity to change. RESULTS: Forty-one participants entered the study and their scores were compared at 3 cross sectional single points. The correlation coefficients among the 4 measures varied from 0.60 to 0.91. Correlation between corresponding domains of the WORC and RC-QOL varied from 0.45 to 0.85. The known group validity was not significantly different among individual sub-scores and total scores. The final SRMs were (1.42), (1.43), (1.44), and (1.54) for the ASES, RCQOL, WORC, and UEFI respectively. CONCLUSION: The WORC and RC-QOL exhibit similar cross-sectional convergent validity in patients suffering from rotator cuff pathology. The sensitivity to change was very close among all scores, with the UEFI having the highest sensitivity. Further research is needed to examine the extent to which each physical or emotional domain contributes to prognostic or therapeutic decision-making

Compression garments and fabric orthoses for rehabilitation and function: a systematic mapping review.

Background/aims: Compression garments, joint supports and dynamic movement orthoses all use elastic fibres and close-fitting designs and have been researched for their effects on movement. There is little cross-referencing between research into these interventions. This review aimed to improve inter-disciplinary understanding by analysing key characteristics of the published evidence. Methods: Systematic mapping reviews identify gaps in an evidence base and identify questions for more in-depth reviews. This review was conducted in-line with current guidance. MEDLINE, CINAHL and Sports Discuss were searched for primary research investigating compression garments and orthoses for movement and function. The following search terms were used: "elastane", "spandex", "Lycra", "elastomer*", "Theratog*", "compression", "Neoprene", "orthotic", "orthosis", "shorts", "garment*", "splint", "brace", "sock*" and "stockings". Studies were screened against predetermined criteria and key study characteristics extracted. Findings: Three hundred and fifty-one studies were selected and analysed. Compression garment research was most common (236 studies), followed by research into joint supports (64 studies) and dynamic movement orthoses (42 studies). Research largely reflects the purpose for which each intervention was originally designed. Common topics investigated include posture and movement control, proprioception and muscle activity. Pressure beneath compression garments was measured in 30% of studies. Conclusions: The review highlights a need for more robust study designs in patient populations and accurate description of interventions. There is a need for a review on the possible effects of compression and support on movement control which should be used to inform future primary research

The Bankart repair versus the Putti-Platt procedure: A randomized study with WOSI score at 10-year follow-up in 62 patients

Background and purpose This randomized study compared clinical results after surgery for posttraumatic shoulder instability with either an anatomical repair or an older, less anatomical but commonly used method. The less anatomical procedure has been considered quicker and less demanding, but it has been questioned regarding the clinical result. We therefore wanted to compare the clinical outcome of the two different procedures. Our hypothesis was that the anatomical repair would give less residual impairment postoperatively

Study protocol subacromial impingement syndrome: the identification of pathophysiologic mechanisms (SISTIM)

<p>Abstract</p> <p>Background</p> <p>The Subacromial Impingement Syndrome (SIS) is the most common diagnosed disorder of the shoulder in primary health care, but its aetiology is unclear. Conservative treatment regimes focus at reduction of subacromial inflammatory reactions or pathologic scapulohumeral motion patterns (<it>intrinsic </it>aetiology). Long-lasting symptoms are often treated with surgery, which is focused at enlarging the subacromial space by resection of the anterior part of the acromion (based on <it>extrinsic </it>aetiology). Despite that acromionplasty is in the top-10 of orthopaedic surgical procedures, there is no consensus on its indications and reported results are variable (successful in 48-90%). We hypothesize that the aetiology of SIS, i.e. an increase in subacromial pressure or decrease of subacromial space, is multi-factorial. SIS can be the consequence of pathologic scapulohumeral motion patterns leading to humerus cranialisation, anatomical variations of the scapula and the humerus (e.g. hooked acromion), a subacromial inflammatory reaction (e.g. due to overuse or micro-trauma), or adjoining pathology (e.g. osteoarthritis in the acromion-clavicular-joint with subacromial osteophytes).</p> <p>We believe patients should be treated according to their predominant etiological mechanism(s). Therefore, the objective of our study is to identify and discriminate etiological mechanisms occurring in SIS patients, in order to develop tailored diagnostic and therapeutic strategies.</p> <p>Methods</p> <p>In this cross-sectional descriptive study, applied clinical and experimental methods to identify intrinsic and extrinsic etiologic mechanisms comprise: MRI-arthrography (eligibility criteria, cuff status, 3D-segmented bony contours); 3D-motion tracking (scapulohumeral rhythm, arm range of motion, dynamic subacromial volume assessment by combining the 3D bony contours and 3D-kinematics); EMG (adductor co-activation) and dynamometry instrumented shoulder radiographs during arm tasks (force and muscle activation controlled acromiohumeral translation assessments); Clinical phenotyping (Constant Score, DASH, WORC, and SF-36 scores).</p> <p>Discussion</p> <p>By relating anatomic properties, kinematics and muscle dynamics to subacromial volume, we expect to identify one or more predominant pathophysiological mechanisms in every SIS patient. These differences in underlying mechanisms are a reflection of the variations in symptoms, clinical scores and outcomes reported in literature. More insight in these mechanisms is necessary in order to optimize future diagnostic and treatment strategies for patients with SIS symptoms.</p> <p>Trial registration</p> <p>Dutch Trial Registry (Nederlands Trial Register) <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2283">NTR2283</a>.</p