Biological reference points are important tools for fisheries management. Reference points are not static, but may change when a population's environment or the population itself changes. Fisheries-induced evolution is one mechanism that can alter population characteristics, leading to "shifting" reference points by modifying the underlying biological processes or by changing the perception of a fishery system. The former causes changes in "true" reference points, whereas the latter is caused by changes in the yardsticks used to quantify a system's status. Unaccounted shifts of either kind imply that reference points gradually lose their intended meaning. This can lead to increased precaution, which is safe, but potentially costly. Shifts can also occur in more perilous directions, such that actual risks are greater than anticipated. Our qualitative analysis suggests that all commonly used reference points are susceptible to shifting through fisheries-induced evolution, including the limit and "precautionary" reference points for spawning-stock biomass, B_lim and B_pa, and the target reference point for fishing mortality, F_0.1. Our findings call for increased awareness of fisheries-induced changes and highlight the value of always basing reference points on adequately updated information, to capture all changes in the biological processes that drive fish population dynamics.
Background: The pathophysiology of acute coronary syndromes (ACS) is now accepted as the rupture or erosion of an atherosclerotic plaque, which initially occurs at the shoulder of the plaque and is followed by intra-plaque thrombosis then spread to the vascular lumen and cause total partial vascular occlusion. MMP-9 is an extracellular matrix degrading enzyme that plays a crucial role in the breakdown of the fibrous cap of plaque and subsequent rupture in the pathogenesis of ACS. Cardiac troponins are currently the most sensitive and specific biochemical markers of myocytes necrosis. Objective: To know the correlation between serum level MMP-9 and serum level of Troponin-I in patients with ACS Method: Study design was cross sectional. Data were collected by consecutive sampling from patients in ICCU ward of RSUP Dr. Sardjito General Hospital, Yogyakarta, from June 2008-August 2010. A questionnaire was used to collect information from patient. After admission, peripheral venous blood was drawn once and measured concentration of serum level of MMP-9 and Troponin-I before definitive thrombolysis. Data were expressed as means ± standard deviation (SD). Correlation between serum level of MMP-9 and serum level of Troponin-I were assessed using Spearman's rank correlations test. A value of p<0.05 was considered statistically significant. Result: There were 139 patients with ACS and comprising 63 patients with STEMI, 27 patients with NSTEMI, and 49 patients with UAP. Means±SD of Troponin-I from all of samples was 9.49±10.47 ng/dL. Mean±SD of MMP-9 from all of samples was 1296.06±729.97 ng/dL. There were significant correlations between MMP-9 and Troponin-I in patients with ACS (r=0.34, p=0.000). Conclusion: There were significant correlations between MMP-9 and Troponin-I in ACS patients in ICCU ward, RSUP Dr. Sardjito General Hospital, Yogyakarta, from June 2008-August 2010.
Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries-induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life-history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries.
The intense fishing mortality imposed on Atlantic cod in Icelandic waters during recent decades has resulted in marked changes in stock abundance, as well as in age and size composition. Using a molecular marker known to be under selection (Pan I) along with a suite of six neutral microsatellite loci, we analysed an archived data set and revealed evidence of distinct temporal changes in the frequencies of genotypes at the Pan I locus among spawning Icelandic cod, collected between 1948 and 2002, a period characterized by high fishing pressure. Concurrently, temporal stability in the composition of the microsatellite loci was established within the same data set. The frequency of the Pan IBB genotype decreased over a period of six decades, concomitant with considerable spatial and technical changes in fishing effort that resulted in the disappearance of older individuals from the fishable stock. Consequently, these changes have likely led to a change in the genotype frequencies at this locus in the spawning stock of Icelandic cod. The study highlights the value of molecular genetic approaches that combine functional and neutral markers examined in the same set of individuals for investigations of the selective effects of harvesting and reiterates the need for an evolutionary dimension to fisheries management.
Decreasing temporal trends in probabilistic maturation reaction norm (PMRN) midpoints, symptomatic of earlier maturation despite environmentally induced variation in growth, have been observed in many exploited fish stocks. Here, we studied the growth and maturation trends of female and male Icelandic cod ( Gadus morhua ) by estimating PMRN midpoints for cohorts 1964–1999 and found evidence that a shift towards maturation at smaller sizes and younger ages has occurred independently of changes in growth, condition, and temperature. Weighting the data with regional survey abundance estimates to account for spatial heterogeneity in maturity status and sampling intensity did not qualitatively affect the temporal trends. Length-at-age also decreased through the study period, which, through simulations, could be attributed to the energetic costs of earlier maturity at maturing age groups but not at younger ages. These findings support the hypothesis that such changes in maturation schedules are not caused by environmental factors alone but could also reflect a genetic change, potentially in response to intensive fishing.
Bathymetric and regional variation in condition of Icelandic cod Gadus morhua in autumn is compared to that previously observed in spring. Once again, contradicting patterns in the hepato-somatic index and a morphometric index of fish condition were observed. The relevance of this persistent spatial variation in condition in relation to emerging evidence of behavioural types is discussed.
In their Policy Forum (“Managing evolving fish stocks,” 23 November 2007, p. [1247][1]), C. Jorgensen et al. propose evolutionary impact assessments (EvoIAs) as a general tool for managing evolving resources. The basis for their proposal is that fisheries-induced evolution (FIE) is the most
Interannual (1993 to 2006), spatial and bathymetric trends in the hepatosomatic index (H) and relative body condition index (Kr) of Atlantic cod Gadus morhua in Icelandic waters were investigated from data collected during annual spring (March) groundfish surveys. Individual stomach content data were analysed to assess the relationship between condition and consumption of capelin Mallotus villosus. Liver condition was found to vary with region and depth, tending to be highest in deeper water and in the northern and eastern regions; where temperatures were relatively cold and capelin consumption relatively high. A continuous decline in condition of cod in waters off the east coast was observed throughout the study period. Mature cod were found to be in significantly better condition than immature cod of the same age, and mature females were in better condition than mature males. Different patterns emerged from the 2 condition indices; little variation in Kr was observed whereas H was found to be a dynamic index of condition, suggesting that these metrics are not equivalent measures of cod bioenergetic condition.
Evolutionary impact assessment is introduced as a framework for quantifying the effects of 29 harvest-induced evolution on the utility generated by fish stocks.
There is a growing body of scientific evidence indicating that fisheries can cause evolutionary responses over time periods as short as 1020 years, in particular in traits such as the onset of maturation. As these changes will most likely result in a reduction of the productivity of a fish stock, management objectives and (precautionary) reference points for sustainable exploitation need to be re-defined, and new objectives and reference points for managing fisheries-induced evolution need to be developed. Current knowledge allows for two generalisations. First, reducing harvest rates will almost always slow the rate and extent of fisheries-induced evolution in most life-history traits. Second, raising a stock's minimum size limit for exploitation well above the size range over which maturation occurs will slow down the rate of evolution in its maturation schedule. To go beyond these generic insights, Evolutionary Impact Assessments (EvoIAs) are proposed to quantify the effects of management measures, through the evolutionary response of specific stocks, on the utility functions defined by managers. The Study Group on Fisheries Induced Adaptive Change [SGFIAC] proposes to further develop this framework in dialogue with fisheries scientists and managers, with the aim of integrating the effects of fisheries-induced evolution into fisheries management advice. Developing EvoIAs in the context of suitable case studies is considered to be the most efficient way for making progress.
There is a growing body of scientific evidence indicating that fisheries can cause evolutionary responses over time periods as short as 1020 years, in particular in traits such as the onset of maturation. As these changes will most likely result in a reduction of the productivity of a fish stock, management objectives and (precautionary) reference points for sustainable exploitation need to be re-defined, and new objectives and reference points for managing fisheries-induced evolution need to be developed. Current knowledge allows for two generalisations. First, reducing harvest rates will almost always slow the rate and extent of fisheries-induced evolution in most life-history traits. Second, raising a stock's minimum size limit for exploitation well above the size range over which maturation occurs will slow down the rate of evolution in its maturation schedule. To go beyond these generic insights, 'Evolutionary Impact Assessments' (EvoIAs) are proposed to quantify the effects of management measures, through the evolutionary response of specific stocks, on the utility functions defined by managers. The Study Group on Fisheries Induced Adaptive Change [SGFIAC] proposes to further develop this framework in dialogue with fisheries scientists and managers, with the aim of integrating the effects of fisheries-induced evolution into fisheries management advice. Developing EvoIAs in the context of suitable case studies is considered to be the most efficient way for making progress.