Local Harvesting Research Articles

Experimental harvest and regrowth in Appalachian black cohosh (Actaea racemosa, Ranunculaceae) populations: Implications for sustainable management of a medicinal forest herb

A broad range of understory forest herbs are harvested for medicinal properties, particularly from species-rich forests of the central and southern Appalachian Mountains. Many species have been collected and used for centuries with little understanding of harvest impacts, some with resulting population declines. Species valued for belowground components, such as Actaea racemosa L. (black cohosh), appear particularly vulnerable to harvest impacts. Between 2005 and 2011, we conducted experimental harvests on natural A. racemosa populations in central Appalachian oak (Quercus L.) forests. Responses were examined during 3 yr of moderate (33% plant removal) and intensive (66% removal) harvest treatments and up to 3 yr of regrowth, to simulate local harvesting practices and assess recovery potential. After 2 yr of moderate harvests, aboveground growth remained similar to controls. However, after 3 yr of moderate harvests or 2 yr of intensive harvests, significant declines were evident. After our third harvest year, leaf area and stem density were 65–80% lower in moderate harvest plots and 80–90% lower in intensive harvest plots, compared with controls. These differences persisted for at least 2 yr after harvests treatments ended. Curve-fitting models suggested recovery of leaf area and mean plant height to preharvest levels after 4–7 yr without further plant removal. In contrast, stem density showed little to no increase during our study period, and model projections suggested declines, rather than recovery. Thus, although individual growth metrics suggested that limited harvesting may be sustainable, results for stem density indicated little new recruitment into the population and concern for long-term population persistence. Forest herbs harvested for belowground components create particular challenges for sustainable management. Our concerns for A. racemosa are applicable to other economically important forest perennials in our region and worldwide and emphasize the need for continued study and monitoring to maintain viable populations and associated natural systems.

Tree-ring evidence of changes in the subarctic forest cover linked to human disturbance in northern Labrador (Canada)

ABSTRACTWe combined dendroecological analyses with historical and ethnographic information to document connections between forest use patterns since the 18th century and stand composition and structure in the Nain region of Labrador, Canada. The highest recruitment periods for both eastern larch and spruce, pulses in growth releases, and decades with greatest harvesting evidence (cut stumps) all occurred primarily between 1910 and 1970. The strongest disturbance signal occurred after 1940, resulting in the absence of old trees and increased larch recruitment. The 1910–1970 period coincides with significant shifts in human settlement and land use patterns. Most notably, the increased demand for fur in the 1920s and 1930s changed Inuit land use: the Inuit spent more time inland where fur-bearing animals and wood resources were available. Moreover, population growth in Nain, which was accelerated by the relocation of Inuit communities in northern Labrador between 1950 and 1960, increased local harvesting intensity. We argue that long-term land use needs to be accounted for as a driver of forest dynamics in this subarctic forest landscape.

How can local representations of changes of the availability in natural resources assist in targeting conservation?

The use and appropriation of natural resources by human groups may be strongly related to the perception that these groups have of the abundance or scarcity of these resources. Researches on environmental representation can be useful to understand the criteria involved in the selection and use of natural resources, to verify if people realize changes in the availability of these resources and the possible causes of these changes and to elaborate conservation strategies, if necessary. However, if people are not realizing these changes, of if they do not perceive themselves as a cause of such scarcity, the developing of conservation strategies will be very difficult to implement. We investigated the drivers of sustainable harvest of Syagrus coronata (Mart.) Becc. (ouricuri palm) leaves by the Fulni-ô indigenous people in northeastern Brazil and accessed the representation of changes in the availability of the populations of this species over time. We obtained information about events that, from the point of view of the palm harvesters, pose threats to S. coronata populations. More experienced local harvesters tend to harvest leaves in a more sustainable manner than did young and inexperienced harvesters. The Fulni-ô reported a decline in S. coronata populations. However, they primarily associate such decline to the farming practices of non-indigenous people that lease lands in the area. Although the Fulni-ô people perceived a shortage of such resource, our findings indicate that the implementation of conservation strategies for the ouricuri palm may not be so easy to implement, once it affects one of their main income sources (land lease), which is recognize as the major threat for the species by harvesters. Ours results showed that the relationship between perception of scarcity and ease of implementation of conservation actions should be contextualized.

SUSTAINABLE PRACTICES IN REAL ESTATE HOUSING IN GHANA: PERCEPTION OF OCCUPANTS

Sustainability has been and continues to be the one recurring topical issue the world over. Governments all over are turning serious attention towards the provision of sustainable urban housing for their urban populace. This they have realised holds the key to leading developmental growth for their economies. Building professionals are now confronted everywhere on green building and construction Ghana as a lower middle income country is grappled with a huge housing demand giving rise to a thriving real estate sector in the capital city. The houses they produce come with exhorbitant cost due to the fact that most of these building features are imported in addition to poor planning and design construction. The paper evaluates the occupiers of this estates house their perception on sustainable housing solutions and their satisfaction levels in the dwellings. Again it sought to investigate the building performance in meeting the occupant’s desired comfort. The study adopted the case study as the most appropriate with quantitative methods and random sampling techniques in sample size and questionaire administration. Data collected were analysed by the spps analytical tools and results presented in tables bar and pie charts. Likert scale ranking from 1-5 were used to rank satisfaction with Habitability Index (HI)formula used determine the actual satisfaction levels. Results indicated that majority of occupiers were aware of sustainability issues. Whilst they acknowledge the opportunities offered they were reluctant in making extra expenditure to get these sustainable solutions. Satisfaction levels were high for site planning, and neighbourhood landscape obtaining Habitability Index above 80%. Provision of natural ventilation, natural lighting, use of local materials energy efficient design and rain water harvesting received satisfaction levels of HI below 50%. The study thus recommends amongst others aspects that further education should be carried out by the key stakeholders on housing delivery; government should foster practising sustainable housing by public private partnerships and offering various incentive packages to participants; and government should establish a regulatory body to oversee the operations of real estate developers. This study would provide vital information on the perceived indicators of Real Estate occupants in Ghana.

Field Data and Stakeholders: Regulating the Commercial Harvest of Snapping Turtles in Maryland

Abstract Turtles are highly susceptible to the negative effects of commercial harvesting. In October 2007, the Maryland Department of Natural Resources convened a Working Group to discuss the snapping turtle (Chelydra serpentina) fishery in Maryland and to make recommendations considered necessary to maintain a sustainable fishery. We collected information on population structure and the collecting techniques used by local harvesters in the field. An increase in the minimum legal size limit from 9.5 inches (24.1 cm) in 2008 to 11 inches (27.9 cm) in 2009 resulted in more females being protected from harvesting yet significantly decreased catch per unit effort, forcing harvesters to increase collecting effort to maintain catch levels.

Cornelian cherry (Cornus masL.) fruit as a non-timber forest product of Arasbaran biosphere reserve forests in Northwest of Iran

AbstractThe present research aimed to quantitatively and economically evaluate Cornelian cherry (Cornus masL.) fruit as a non-timber forest product for a resident rural community across three consecutive years. A forest stand of 50 hectares in Kalaleh village, Northwest of Iran (Arasbaran biosphere reserve), was selected. After estimating the number of stems per hectare, the rate of fruit production rate was determined. Forty five individuals were then selected and assessed for their vegetative characteristics, including total height (m), crown height (m), crown diameter (m), diameter at breast height (mm), number of coppice shoots and annual fruit production (kg). Relationships between the vegetative characteristics and fruit production were then determined using multiple regression analysis to estimate the total fruit production per ha (estimated number of stems per hectare x mean fruit production per stem). Questionnaires and interviews were conducted to determine the number of stakeholders, quantity of fruit harvested and their harvesting methods; in addition to the costs and revenues of the harvest. Our results indicated that in 2012, 2013 and 2014, the annual total fruit production and local harvesting rates were: (i) 17 500, 10 705 and 8 169 kg and (ii) 4 900, 6 540 and 6 700 kg respectively. The revenue from selling the fruit contributed from 3.6% to 7.3% to household livelihoods. Mean economic rent of Cornelian cherry utilization and the average expected value of the forest were US$ 52.9 and US$ 17.6 respectively, while the average marketing margin of utilization was 65.5%. We believe that the inflated harvest rate recorded in 2014, which was above the allowable quota, might be a crucial threat to viability and also the sustainability of the forest stand. In conclusion, launching and implementing non-timber forest products projects including tree domestication is required to help conserving biodiversity in one hand and to sustainably manage natural resources in the other hand.

Strategies towards sustainable bark sourcing as raw material for plant-based drug development: a case study on <i>Garcinia lucida</i> tree species

Objectives : To appraise the amount of sustainable bark stripped and time to complete bark recovery as basis for sourcing of raw materials for plant-based drugs Methodology and Results : A two-year experiment was conducted and several local harvest practices were tested on Garcinia lucida (named Essok in Boulou language). For each harvest method, 20 healthy trees were selected and harvested. Tree health was monitored every month and the total bark regrowth was calculated using planimetric techniques. The mean bark mass was 2.54 kg/tree (range, 0.5-15 kg/tree; SD, 2.40; n=80) and increased with bark thickness, ranging from 1.28 kg tree-1 (0.4-0.8 cm thin) to 4.38 kg tree-1(1.2 – 1.8 cm thick). The mean rate of bark regeneration was 787±601 cm²/tree/year (range, 452±166-1870±1042 cm²/tree/yr; n=53) and positively correlated to harvest method (p < 0.01) and surface debarked (p < 0.05). Standard Deviation values were higher, suggesting that each tree had its proper bark growth rate patterns, and that bark regrowth process may be tree-specific and strongly correlated to intrinsic factors. Conclusions and application of findings : Peeling off pieces of bark using a machete and debarking over 1/3 of the stem circumference at breast height, once every 3 years for small trees or every 5 years for large trees, has been found to be the best harvest method for G. lucida species. This is to tackle the challenge of availability of raw material and harvest sustainability. As the increased trade and processing of bark has shifted from subsistence use to large-scale commercial use, posing a threat to supply of raw material and species conservation, sustainable harvesting methods should constitute important tools of the guidelines on good collection practices for medicinal plants that would help to ensure safety and quality at the first and most important stage of the harvest of medicinal plants. This study has provided information on the species-specific bark harvest prescriptions to assist in developing such guidelines, thereby promoting the processing and trade of the most valued medicinal species for plant-based drug development in Africa. Keywords : Garcinia lucida , medicinal plant, bark, raw material, sustainable bark stripping.

Decline of the Manila clams stock in the northern Adriatic lagoons

The Manila clam, Ruditapes philippinarum, introduced in the Venice lagoons in 1983 and rapidly spread to the nearby coastal lagoons represents one of the most important commercially-exploited resources of this area. Abundance, size-class and biomass distribution of the wild population living in the Pialassa Baiona lagoon were assessed and related to the hydrological and sediment characteristics. Despite the lagoon being affected by eutrophication, chemical and thermal pollution, the clams were harvested by about thirty professional fishermen until 2003. The commercially available stock was estimated at 36.8 10 3 kg in July 2002, 29.3 10 3 kg in April 2003, and 10.3 10 3 kg in October 2003. Stock estimations and observed mortality were in good accordance with the fishermen data. The decline of the available stock could be due to both overfishing and the extraordinary summer heat wave occurred in 2003, which may have reduced larval recruitment and increased the mortality. Overall, the juvenile recruitment appeared insufficient to annually restore the natural stock. Although the national and regional high relevance of clams market, local harvesting of wild populations appeared marginal and inadequate to support a remunerative commercial activity, due to the variability and unpredictability of the annual yield and the lack of a sustainable management based on a production chain’s approach.

Shake-and-Catch Harvesting for Fresh Market Apples in Trellis-Trained Trees

Currently, fresh market apples are picked manually around the globe, which has become a challenge due to the decreasing availability of labor and the high associated cost. To reduce harvest cost and dependence on human labor, researchers and growers have been seeking mechanical solutions for decades. However, the high rate of harvest-induced fruit damage has been an obstacle to commercializing these technologies. To achieve a desirable level of fruit quality with mechanical harvesting, a new shake-and-catch system with two catching buffers for reducing fruit impact was developed and evaluated in this study. The system provides localized harvesting by shaking targeted tree limbs and catching the detached fruits directly under the limbs. To test the performance of the catching device, a series of laboratory tests was conducted using an impact recording device. The results showed that the impact force of falling fruit and the number of impacts decreased dramatically when using a catching surface with buffers compared to using a catching surface without buffers. A harvesting test was performed with ‘Jazz‘ apple trees trained to vertical fruiting wall architecture. The system achieved fruit removal efficiencies of 84%, 86%, and 92% for shaking frequencies of 15, 20, and 25 Hz, respectively. The corresponding collection efficiencies were 99%, 98%, and 93%. The system achieved the highest quality grade (Extra Fancy) for 85% of the harvested fruits when the limb was shaken at 15 Hz and fruits were collected using a catching surface tilted at an angle of 25°. With this level of performance of the prototype system, this study showed that the developed shake-and-catch system offers a promising solution for mechanical harvesting of ‘Jazz‘ apples, with potential extension to other apple varieties grown in modern fruiting wall architectures.

Transitions of social-ecological subsistence systems in the Arctic

Transitions of social-ecological systems (SES) expose governance systems to new challenges. This is particularly so in the Arctic where resource systems are increasingly subjected to global warming, industrial development and globalization which subsequently alter the local SES dynamics. Based on common-pool resource theory, we developed a dynamic conceptual model explaining how exogenous drivers might alter a traditional subsistence system from a provisioning to an appropriation actions situation. In a provisioning action situation the resource users do not control the resource level but adapt to the fluctuating availability of resources, and the collective challenge revolve around securing the subsistence in the community. An increased harvest pressure enabled by exogenous drivers could transform the SES to an appropriation action situation where the collective challenge has changed to avoid overuse of a common-pool resource. The model was used as a focal lens to investigate the premises for broad-scale transitions of subsistence-oriented SESs in Arctic Alaska, Canada and Greenland. We synthesized data from documents, official statistics and grey and scientific literature to explore the different components of our model. Our synthesis suggests that the traditional Arctic subsistence SESs mostly comply with a provisioning action situation. Despite population growth and available technology; urbanization, increased wage labor and importation of food have reduced the resource demand, and we find no evidence for a broad-scale transition to an appropriation action situation throughout the Western Arctic. However, appropriation ­challenges have emerged in some cases either as a consequence of commercialization of the resource or by severely reduced resource stocks due to various exogenous drivers. Future transitions of SESs could be triggered by the emergence of commercial local food markets and Arctic warming. In particular, Arctic warming is an intensifying exogenous driver that is threatening many important Arctic wildlife resources inflicting increased appropriation challenges to the governance of local harvest.

Bridging science and traditional knowledge to assess cumulative impacts of stressors on ecosystem health

Cumulative environmental impacts driven by anthropogenic stressors lead to disproportionate effects on indigenous communities that are reliant on land and water resources. Understanding and counteracting these effects requires knowledge from multiple sources. Yet the combined use of Traditional Knowledge (TK) and Scientific Knowledge (SK) has both technical and philosophical hurdles to overcome, and suffers from inherently imbalanced power dynamics that can disfavour the very communities it intends to benefit. In this article, we present a ‘two-eyed seeing’ approach for co-producing and blending knowledge about ecosystem health by using an adapted Bayesian Belief Network for the Slave River and Delta region in Canada's Northwest Territories. We highlight how bridging TK and SK with a combination of field data, interview transcripts, existing models, and expert judgement can address key questions about ecosystem health when considerable uncertainty exists. SK indicators (e.g., bird counts, mercury in fish, water depth) were graded as moderate, whereas TK indicators (e.g., bird usage, fish aesthetics, changes to water flow) were graded as being poor in comparison to the past. SK indicators were predominantly spatial (i.e., comparing to other locations) while the TK indicators were predominantly temporal (i.e., comparing across time). After being populated by 16 experts (local harvesters, Elders, governmental representatives, and scientists) using both TK and SK, the model output reported low probabilities that the social-ecological system is healthy as it used to be. We argue that it is novel and important to bridge TK and SK to address the challenges of environmental change such as the cumulative impacts of multiple stressors on ecosystems and the services they provide. This study presents a critical social-ecological tool for widening the evidence-base to a more holistic understanding of the system dynamics of multiple environmental stressors in ecosystems and for developing more effective knowledge-inclusive partnerships between indigenous communities, researchers and policy decision-makers. This represents new transformational empirical insights into how wider knowledge discourses can contribute to more effective adaptive co-management governance practices and solutions for the resilience and sustainability of ecosystems in Northern Canada and other parts of the world with strong indigenous land tenure.

The community of Mata de Limón, central Pacific coast of Costa Rica and the extraction of colonchos Callichirus seilacheri (Bott, 1955) (Decapoda: Axiidea: Callianassidae)

We conducted monthly visits to the coastal community of Mata de Limón (December 2011 to November 2012) in central Pacific of Costa Rica for assessment the extraction of the burrowing shrimp called coloncho Callichirus seilacheri, a species intensely caught as bait for fishing along the Pacific coast of Central America. The outcomes indicate that fishery effort varied between 4 and 14 harvesters day-1 with a high percentage of them from the same community (70-100%). Daily catch varied between 76 and 1120 shrimps and its value was strongly correlated with catches realized for the local harvesters (R2= 0.88). The shrimps density and total abundance in Mata de Limón was estimated in 1.2 ± 0.88 ind m-2 and 49,607 ± 3,638 individuals, respectively. Ovigerous females were exclusively present between May and November, peak in September. According to our outcomes, population of C. seilacheri in Mata de Limón could be in risk of overfishing if the daily catches exceed 800 individuals. The main results of the present study allow recommend the implementation of a total fishing ban during the reproduction peak of C. seilacheri directed to protection and conservation of this local resource for its sustainable harvesting. Also, we suggest the establishment of a management program between the community of Mata de Limón and the Instituto Costarricense de Pesca y Acuicultura (INCOPESCA) in order to optimize and legalize the extraction of this important resource.

How do fire and harvesting affect the population dynamics of a dominant endemic Velloziaceae species in campo rupestre?

Understanding the role of the environmental drivers that determine plant population dynamics is essential to promote the conservation of target species and their habitats. Vellozia aff. sincorana is an endemic key species from the rupestrian grasslands (campos rupestres) of the Chapada Diamantina region in the Brazilian savanna (Cerrado). The branches are important in the local culture and are harvested to light wood stoves. Synchronized flowering is triggered by fire, and no flowers have been recorded in the absence of a recent fire. We built matrix population models to project the demography of six V. aff. sincorana populations, three that had recently burned and three that had not burned for four years. Based on local harvesting practices and our population models, we assessed the long-term effects of two common harvesting techniques and different fire intervals on this species’ demography. Fire is necessary for the long-term persistence of V. aff. sincorana populations; adult survival is the most important vital rate for population persistence and it is mostly unaffected by fire. Recent fires primarily caused increases in reproductive rates, and populations are projected to decrease in size (λ<1) under fire intervals longer than 25 years. Harvest effects depend on its frequency and intensity; our models indicated that harvesting may be sustainable as long as it is low-intensity and fire also occurs periodically. As in many other fire-prone ecosystems, this species benefits from fire occurrence. These results indicate that the ‘zero-fire’ policy currently in place in the Brazilian savanna is inadequate for the conservation of this, and probably many other, Cerrado species.

Socio-economic, operational and technical characterisation of the harvesting of gooseneck barnacle (Pollicipes pollicipes) in SW Portugal: Insights towards fishery co-management

The present study characterised the socio-economic, operational and technical aspects of harvesting the gooseneck barnacle (Pollicipes pollicipes) along the southwestern coast of Portugal. For this purpose, face-to-face interviews were conducted with commercial harvesters of the two most representative fishery associations (covering 51% licensed harvesters) in the area of the Parque Natural do Sudoeste Alentejano e Costa Vicentina. Based on traditional ecological knowledge, this study confirmed the local importance, ancestral character and family traditions of this activity, which constitutes the exclusive occupation of nearly half of the interviewed harvesters and an important source for household incomes. In addition, data was also gathered on preferential fishing zones, harvesting effort and duration, daily catches and selling prices. The main concerns, problems and difficulties experienced in this activity relate to the excessive number of recreational harvesters, creating problems at the levels of exploitation, commercialisation, management and inspection. The study further confirms the rising interest and involvement of the commercial harvesters in enhancing the competences of the local fishery associations. In particular, local harvesters want to encourage the development of a co-management system comprising spatial-temporal measures to avoid conflicts of use over space and resources, as well as innovative marketing strategies to improve the recognition, value and traceability of the shellfish. Overall, the information gathered is most valuable for adopting an alternative approach based on the cooperation and co-responsibility at local and regional levels, involving the stakeholders in the proposal of management measures adapted to the specificities of this area, activity and resource.

Molecular Characterization of Sclerocarya birrea ICRAF Field Genebank Collections

Scelerocarya birrea is an important fruit tree that is widely used by the rural populations in most regions in which it is found, for its fruits, bark, timber and even its roots. The local communities harvest the tree products from the wild with minimal attempts to grow it on-farm. The sustainability of such wild harvests is threatened by agriculture, overgrazing and overexploitation for other purposes. Therefore, the species needs urgent conservation measures in addition to selecting superior germplasm for on-farm tree management that will facilitate ease of species cultivation. This has prompted the International Center for Research in Agroforestry (ICRAF) and partners to collect and manage S. birrea germplasm in field genebanks as the initial step towards the species domestication and conservation. In order to effectively manage germplasm, it is important to establish the collection genetic diversity. Six ISSR markers yielded a total of 76 polymorphic bands across the 257 accessions studied. Percentage of polymorphic loci and observed heterozygosity ranged from 75% to 7.89% and H=0.362 to H=0.043, respectively. The partitioning of genetic diversity found a higher (86% P>0.001) intra-population variation and low inter-population variation, typical of the outcrossing nature of S. birrea. According to Jaccard’s dissimilarity index, the highest genetic distance between accessions was 1.000 and the least genetic distance was 0.000. Neighbour-joining clustering grouped the accessions into three major clusters and twenty probable duplicates were identified, which should be eliminated to cut down the cost of conservation. The results obtained suggest that S. birrea ICRAF field genebank collections have a comparatively rich gene pool and, hence, valuable for conservation of S. birrea. The twenty samples showing duplicates would be good for evaluating performance of this long-lived tree species in both locations.

Interactive Effects of Water Temperature and Salinity on Growth and Mortality of Eastern Oysters,Crassostrea virginica: A Meta-Analysis Using 40 Years of Monitoring Data

Despite nearly a century of exploitation and scientific study, predicting growth and mortality rates of the eastern oyster (Crassostrea virginica) as a means to inform local harvest and management activities remains difficult. Ensuring that models reflect local population responses to varying salinity and temperature combinations requires locally appropriate models. Using long-term (1988 to 2015) monitoring data from Louisiana's public oyster reefs, we develop regionally specific models of temperature- and salinity-driven mortality (sack oysters only) and growth for spat ( 75 mm) oyster size classes. The results demonstrate that the optimal combination of temperature and salinity where Louisiana oysters experience reduced mortality and fast growth rates is skewed toward lower salinities and higher water temperatures than previous models have suggested. Outside of that optimal range, oysters are commonly exposed to combinations of temperature and salinity that are correlated with high mortality and reduced growth. How these combinations affect growth, and to a lesser degree mortality, appears to be size class dependent. Given current climate predictions for the region and ongoing large-scale restoration activities in coastal Louisiana, the growth and mortality models are a critical step toward ensuring sustainable oyster reefs for long-term harvest and continued delivery of the ecological services in a changing environment.

Gone with the Storm: Rainfall Shocks and Household Wellbeing in Guatemala

ABSTRACTThis paper identifies the negative consequences of the strongest tropical storm ever to strike Guatemala on household welfare. Per capita consumption fell in urban areas, raising poverty substantially. Households cut back on food consumption and basic durables, and attempted to cope by increasing their adult and child labour supply. The mechanisms at play include the intensity of the shock, food prices and the timing of Agatha with respect to local harvest cycles. The results are robust to placebo treatments, migration and measurement error, and partly explain the increase in poverty in the country previously attributed solely to the collateral effects of the global financial crisis.

Hunting migratory geese: is there an optimal practice?

Since the mid‐20th century, many European and North American goose populations have increased dramatically in numbers, causing conflict with agricultural interests in their staging and wintering areas. In some cases, to mitigate such impacts of rapid population increases, population control has been attempted by increasing harvest rate. In this study, we investigated how autumn‐staging pink‐footed geese Anser brachyrhynchus responded to hunting, with a view to determine hunting practice that would lead to an increase in the hunting bag. There was a significant increase in the distance between the hunting site and the goose flocks, on comparing goose distribution on the day before the hunt up to one day after the hunt. The effect was significant when at least 10 shots were fired per site but not when 1–10 shots were fired. The timing of shooting in relation to migratory phenology did not affect the time taken by the geese to return to the hunting site, but after a hunt in the early part of the staging season, the number of geese in the study area increased more rapidly than towards the end of the season. The maximum number of geese shot per hunting event was obtained when hunting events were separated by three days. Our results indicate that hunters can increase local harvest by temporal and spatial optimisation of practices. These results may be used as a tool in wider‐scale regional and international processes to regulate the population size of pink‐footed geese by shooting, depending on the willingness of landowners, hunters and managers to coordinate hunting practices.

Detecting black bear source-sink dynamics using individual-based genetic graphs.

Source-sink dynamics affects population connectivity, spatial genetic structure and population viability for many species. We introduce a novel approach that uses individual-based genetic graphs to identify source-sink areas within a continuously distributed population of black bears (Ursus americanus) in the northern lower peninsula (NLP) of Michigan, USA. Black bear harvest samples (n = 569, from 2002, 2006 and 2010) were genotyped at 12 microsatellite loci and locations were compared across years to identify areas of consistent occupancy over time. We compared graph metrics estimated for a genetic model with metrics from 10 ecological models to identify ecological factors that were associated with sources and sinks. We identified 62 source nodes, 16 of which represent important source areas (net flux > 0.7) and 79 sink nodes. Source strength was significantly correlated with bear local harvest density (a proxy for bear density) and habitat suitability. Additionally, resampling simulations showed our approach is robust to potential sampling bias from uneven sample dispersion. Findings demonstrate black bears in the NLP exhibit asymmetric gene flow, and individual-based genetic graphs can characterize source-sink dynamics in continuously distributed species in the absence of discrete habitat patches. Our findings warrant consideration of undetected source-sink dynamics and their implications on harvest management of game species.

Relevance of F-Specific RNA Bacteriophages in Assessing Human Norovirus Risk in Shellfish and Environmental Waters.

Human noroviruses (HuNoVs) are the main cause of shellfish-borne gastroenteritis outbreaks. In the absence of routine technical approaches allowing infectious particles to be detected, this viral pathogen is currently targeted by genome research, leading to difficult interpretations. In this study, we investigated the potential of F-specific RNA bacteriophages (FRNAPH) as fecal and viral contamination indicators in shellfish and water from a local harvesting area. FRNAPH were also used as microbial source tracking tools. Constraints imposed by detection limits are illustrated here by the detection of infectious FRNAPH in several samples in the absence of FRNAPH genomes. The opposite situation was also observed, likely explained by the persistence of the genomes being greater than infectivity. Similar considerations may be applied to HuNoVs, suggesting that HuNoV genome targeting is of limited relevance in assessing infectious risks. While FRNAPH did not provide any benefits compared to Escherichia coli as fecal pollution indicators in water, novel observations were made in shellfish: contrary to E. coli, a seasonal trend of infectious FRNAPH concentrations was observed. These concentrations were higher than those found in water, confirming bioaccumulation in shellfish. This study also underlines a relationship between the presence of HuNoV genomes and those of human-specific FRNAPH subgroup II (FRNAPH-II) in shellfish collected throughout Europe. Further research should be undertaken to evaluate FRNAPH potential as an indicator of the presence of infectious HuNoVs. To this end, shellfish involved in HuNoV-caused gastroenteritis outbreaks should be analyzed for the presence of infectious FRNAPH-II. This work provides new data about the use of F-specific RNA phages (FRNAPH) as a tool for evaluating fecal or viral contamination, especially in shellfish. In our case study, FRNAPH did not provide any benefits compared to E. coli as fecal pollution indicators in water but were found to be very useful in shellfish. Their concentrations in shellfish were higher than those found in the surrounding water, confirming bioaccumulation. This study also underlines a relationship between the presence of human norovirus genomes (HuNoVs) and those of FRNAPH subgroup II (FRNAPH-II). Considering that the two virus types have similar behaviors and since FRNAPH infectivity can be investigated, the specific detection of infectious FRNAPH-II could be regarded as an indication of the presence of infectious HuNoVs. The contribution of infectious human FRNAPH targeting for assessing the viral risk associated with HuNoVs in shellfish should thus be investigated.