Decline In Harvest Research Articles

Trends in Subsistence Harvests of Ice Seals in the Yukon-Kuskokwim Delta Region, Alaska, 1962 – 2018

Ringed (Pusa hispida), bearded (Erignathus barbatus), spotted (Phoca largha), and ribbon seals (Histriophoca fasciata), or ice seals, are harvested for subsistence purposes by many Alaska Native communities. We address trends in the subsistence harvest of ice seals for the Yukon-Kuskokwim Delta region of Alaska for more than 50 years using two types of data collected by the Alaska Department of Fish and Game: (1) bounty data collected from 1962 to 1972 for 16 communities, and (2) household survey data collected for seven of these communities from 1997 to 2018. Both include information on the number of ice seals harvested by each community annually. In addition, more detailed household surveys were conducted from 2008 to 2018 for Hooper Bay, Tununak, and Quinhagak, which collected data on the number of seals harvested by species, the percentage of households engaged in hunting or using seal products, and hunter perceptions. For the bounty period, we identified several years where most communities had above or below average harvests, suggesting regional drivers contributed to patterns in the ice seal harvest. For the seven communities with household survey data, the mean total harvest estimate during the household survey years was only slightly lower than during the bounty period, however, the human population doubled during this time, resulting in a substantial decline in the mean number of seals harvested per person. The more detailed surveys for Hooper Bay, Tununak, and Quinhagak also showed declines in seal harvests during the most recent decade. The declining harvest in some communities may be driven by reduced participation in hunting and less use of seal products. Ongoing sea ice loss is also likely contributing to the decline in harvest across the region. Current seal population estimates indicate all four species are abundant in Alaskan waters, and most hunters have not observed changes in seal abundance.

ANALYSIS OF CRITICAL LAND USING FOREST CANOPY DENSITY METHOD IN THE AGROPOLITAN DEVELOPMENT AREA OF LAMONGAN REGENCY

Abstract: Critical land is a form of degraded land. The biophysical condition of the land that tends to decline causes a decrease in agricultural productivity, the environment, and food availability and is caused by the unwise use of natural resources. This research will be conducted in the southern part of Lamongan Regency which focuses on agropolitan rainfed rice fields which have experienced some decline in harvest yields in the last year. The research method is an analysis of the distribution of critical land using a Geographic Information System which is divided into main stages, namely: database development and data analysis, which begins with data collection, supporting maps, and literature study. The critical level of land in agropolitan areas in Lamongan Regency is divided into 5 categories, namely Not Critical, Potentially Critical, Slightly Critical, Critical and Very Critical but the very critical category turns out that there is no land that falls into that category so there are only 4 categories of critical land which shows that the land is classified as critical. non-critical area is 125.44 ha with a percentage of 0.24, Critical Potential area is 38736.37 ha with a percentage of 74.80%, somewhat critical category covers an area of 12827 with a percentage of 24.77%, and Critical Category covers an area of 100.28 ha with a percentage of 0 ,19%Keywords: Critical Land, Forest Canopy Density, AgropolitanAbstrak:

Tracking the decline of weasels in North America.

Small carnivores are of increasing conservation concern globally, including those formerly thought to be widespread and abundant. Three weasel species (Mustela nivalis, M. frenata, and M. erminea) are distributed across most of North America, yet several recent studies have reported difficulty detecting weasels within their historical range and several states have revised the status of weasels to that of species of conservation concern. To investigate the status and trends of weasels across the United States (US) and Canada, we analyzed four separate datasets: historical harvests, museum collections, citizen scientist observations (iNaturalist), and a recent US-wide trail camera survey. We observed 87–94% declines in weasel harvest across North America over the past 60 years. Declining trapper numbers and shifts in trapping practices likely partially explain the decline in harvest. Nonetheless, after accounting for trapper effort and pelt price, we still detected a significant decline in weasel harvest for 15 of 22 evaluated states and provinces. Comparisons of recent and historical museum and observational records suggest relatively consistent distributions for M. erminea, but a current range gap of >1000 km between two distinct populations of M. nivalis. We observed a dramatic drop-off in M. frenata records since 2000 in portions of its central, Great Lakes, and southern distribution, despite extensive sampling effort. In 2019, systematic trail camera surveys at 1509 sites in 50 US states detected weasels at 14 sites, all of which were above 40o latitude. While none of these datasets are individually conclusive, they collectively support the hypothesis that weasel populations have declined in North America and highlight the need for improved methods for detecting and monitoring weasels. By identifying population declines for small carnivores that were formerly abundant across North America, our findings echo recent calls to expand investigations into the conservation need of small carnivores globally.

ВЛИЯНИЕ АБИОТИЧЕСКИХ ФАКТОРОВ НА УРОЖАЙ АБРИКОСА В УСЛОВИЯХ ЮЖНОГО УРАЛА

The productivity of apricot plantations in the Urals is limited by the irregularity of fruiting due to poor fruit bud winter hardiness in a majority of introduced cultivars. In 1999–2016, a research project was underway at the Department of Horticulture, Southern Ural Research Institute of Horticulture and Potato Growing, aimed at studying the apricot collection accessions of diverse geographic origin under the climate conditions of the Southern Urals. Such a long-term study made it possible to identify abiotic factors affecting the yield of this crop as well as to select highly adaptive and high-yielding cultivars for the Southern Urals: ‘Prizer’ (9.4 kg/tree), ‘Snezhinsky’ (9.2 kg/tree), ‘Kichiginsky’ (9.0 kg/tree) and ‘Uralets’ (8.5 kg/tree). Among the studied genotypes there were tree forms with irregular fruiting pattern, characterized by low resistance to adverse effects of abiotic factors: ‘Khabarovsky’ (0.9 kg/tree) and ‘Michurinsky No. 22’ (0.3 kg/tree). In the environments of the Southern Urals, critical winters (continuous frosts of –40°C) considerably damage generative buds, which results in having no apricot harvest in such years. Despite the harsh winters, annual shoots of local apricot-trees tended to freeze only to a small degree. Field survey of the apricot plantations showed that generative buds of local apricot cultivars (‘Kichiginsky’, ‘Prizer’, ‘Snezhinsky’ and ‘Uralets’) could withstand frosts of –40... –43°С (2003) only if they were brief, while continuous frosts destroyed them completely (2006, 2010). In addition, a decline in harvest was observed as a result of springtime frosts and temperature fluctuations in the end of winter (1999, 2014). Despite the abundant flowering in 2001, 2015 and 2016, the yield of apricot trees was low due to the frosts during the flowering period. Productivity of apricot trees also depends on their genetic characteristics, and in particular, on the geographical origin of cultivars. The introduced cultivars ‘Khabarovsky’ and ‘Michurinsky No. 22’ yielded fruit only thrice during the entire period of research.

Carbon stocks and timber harvest. Alternative policy approaches for the Great Bear rainforest and their consequences

Forest policy-making can be dramatically enhanced by implementing computer based decision support systems (DSS) during the development phase. While stakeholders usually agree on general policy objectives, the best course of action for achieving them is often unclear. Forest DSS can support the assessment of alternative forest policy frameworks with respect to their impact on multiple variables of interest for stakeholders and decision makers, yet, these tools are often underutilised.In January 2016 a new land use order policy for the Great Bear Rainforest (GBR) in Canada, the largest coastal temperate rainforest in the world, was legally established. The GBR order aims to support ecosystem-based management and legally binding objectives to ensure the long term health of this unique area. This new policy framework will lead to a dramatic decrease in timber harvest levels. We developed 5 alternative forest management scenarios with a less abrupt decline in harvest levels, including carbon sequestration as an option to economically buffer the expected declines in yield. We modelled the development of the forest resources in the area under each scenario over a timeframe of 350years. In doing so we were able to show how the use of computer based DSS is able to assist policy making by providing a comprehensive assessment of consequences associated with the alternatives, to ensure that long term targets are met.Our results show that currently, the GBR stores around 1.73Bt carbon, a number that will increase to 1.84Bt under the GBR order. While it is possible to increase carbon storage by up to 8% when lowering overall timber harvest by 36% over a timeframe of 350years, naturally, those scenarios with a less dramatic decline in timber harvest were related to an overall lower level of carbon stocks. Combined approaches though, which allow balancing timber harvests with ecosystem integrity, are a powerful alternative to a dramatic and abrupt decrease in harvest levels. The success of combined approaches does heavily depend on timber and carbon markets though. With notoriously cyclical markets the long term economy related to the implementation of the new GBR order remains uncertain when looking at carbon and timber markets only, strongly suggesting to rely on diversification and the creation of added value products.

The carry‐over effects of pollen shortage decrease the survival of honeybee colonies in farmlands

Summary Many studies have reported honeybee colony losses in human‐dominated landscapes. While bee floral food resources have been drastically reduced over past decades in human‐dominated landscapes, no field study has yet been undertaken to determine whether there is a carry‐over effect between seasonal disruption in floral resource availability and high colony losses. We investigated if a decline in the harvest of pollen by honeybees in spring affected managed honeybee colony dynamics (brood size, adult population and honey reserves) and health (Varroa mite loads and colony survival) throughout the beekeeping season. A decline in pollen harvest was associated with a direct reduction in brood production, leading to a negative effect on the adult population size later in the season, and lower honey reserves before the onset of winter. Furthermore, the decline in pollen harvest negatively impacted the health of the colony, resulting in higher Varroa mite loads and higher seasonal and winter colony losses. Early‐warning signs of these carry‐over effects were identified, showing that preferential investment in honey reserves instead of brood production early in the season increased the decline in pollen harvest and its associated carry‐over effects. Synthesis and applications. The results suggest that the decline in pollen harvest may have been overlooked as a cause of pollen shortage and associated bee colony losses. Strategies to avoid such losses in intensive farmland systems include (i) limiting or avoiding honey harvests in spring, (ii) monitoring colonies for early‐warning signals of colony failure and (iii) increasing the amount of floral resources available through wise land‐use management.

Reduced migration under climate change: evidence from Malawi using an aspirations and capabilities framework

For farmers in rural Africa, climate change could significantly alter the natural environment, leading to a loss of income, food security and well-being; however, much remains unknown about the way a change in climate may affect a person's decision to migrate away from their home. Using a framework based on migration aspirations and capabilities, this paper examines how climate stresses (such as droughts that cause a long-term decline in harvests) and climate shocks (i.e. acute food shortages and sudden flooding) may affect migration decision-making in rural Malawi. Drawing on survey (n = 255), interview (n = 75) and focus group (n = 93) data from rural and urban dwellers, we find that climate stresses typically do not change rural dwellers’ aspiration to leave their homes, except for a small group of younger farmers from better-off households. However, these same stresses may erode human, financial and social capital, thus reducing migration capability. Data also reveal that acute shocks erode both the migration aspirations and capabilities of even the most dedicated would-be migrant. Drawing from these two findings, this paper concludes that climate change is likely to increase barriers to migration rather than increasing migration flows in countries like Malawi where the economy is still predominately rural.

Assessment of the Middle Mississippi River Channel Catfish Population

Harvest regulations are important for fishes that are both commercially and recreationally sought after such as Channel catfish (Ictalurus punctatus) throughout the Middle Mississippi River. Monitoring total harvest and understanding Channel catfish population dynamics (i.e., recruitment, growth, and mortality) are crucial for managing a sustainable population. Total commercial harvest and current harvest regulations in the Middle Mississippi River have not recently been evaluated. Thus, we evaluated total commercial harvest reports from 1945–2012 along with commercial fishing effort, population dynamics for the Middle Mississippi River Channel catfish population, and simulated the effects of various length limits on the reproductive potential and yield per recruit of the Channel catfish population. Overall, total commercial harvest has drastically declined from 1990–2012, while commercial effort has remained relatively constant. We speculate overexploitation as a possible cause to the decline in harvest ...

Harvesters’ perceptions of population status and conservation of Chinese caterpillar fungus in the Dolpa region of Nepal

Chinese caterpillar fungus is in spotlight because of its high market value, unusual life history, and numerous medicinal uses. One of the most expensive biological resources of the world, Chinese caterpillar fungus is harvested by the most impoverished communities of the Himalaya to sustain their livelihoods. Skyrocketing international trade and intensive local collections from the wild have raised concerns about the status of natural populations and their conservation. We assessed harvesters’ perceptions of the population status of Chinese caterpillar fungus, causes of decline, and sustainable harvesting in Dolpa, Nepal. Most harvesters (95.1 %) believe that the abundance of Chinese caterpillar fungus has decreased during the last 5 years. This belief is supported by trends in average annual per capita harvest. Climate change, over harvesting, premature harvesting, and reduced number of the larvae are the cited causes of decline in harvests. To validate the harvester’s perceptions of climate change, we analyzed temperature and precipitation data. Pearson’s Chi-square tests between the perceptions of abundance of Chinese caterpillar fungus and demographic variables such as harvesting experience, age, place of origin and education are not significant, indicating that the perceptions are independent of demographic characteristics of harvesters. A large proportion of harvesters (79.31 %) believe that the population might recover if collection is periodically banned for 1–2 years. Other protection measures suggested by the harvesters include changes in the harvesting time, regulation of prices, protection of habitat including solid waste management and control of cattle grazing, and development of local capacity for harvesting on a sustainable basis. A systematic management plan that incorporates trans-national efforts to sustain populations that occur across several countries facing similar human and physical pressures and ecological impacts is needed.

Lack of trophic competition among wild and hatchery juvenile chum salmon during early marine residence in Taku Inlet, Southeast Alaska

Early marine trophic interactions of wild and hatchery chum salmon (Oncorhynchus keta) were examined as a potential cause for the decline in harvests of adult wild chum salmon in Taku Inlet, Southeast Alaska. In 2004 and 2005, outmigrating juvenile chum salmon were sampled in nearshore habitats of the inlet (spring) and in epipelagic habitat at Icy Strait (summer) as they approached the Gulf of Alaska. Fish were frozen for energy density determination or preserved for diet analyses, and hatchery stocks were identified from the presence of thermal marks on otoliths. We compared feeding intensity, diets, energy density, and size relationships of wild and hatchery stocks (n = 3123) across locations and weeks. Only hatchery fish feeding intensity was negatively correlated with fish abundance. In both years, hatchery chum salmon were initially larger and had greater energy density than wild fish, but lost condition in early weeks after release as they adapted to feeding on wild prey assemblages. Diets differed between the stocks at all inlet locations, but did not differ for hatchery salmon between littoral and neritic habitats in the outer inlet, where the stocks overlapped most. Both diets and energy density converged by late June. Therefore, if density-dependent interactions affect wild chum salmon, these effects must be very rapid because survivors in Icy Strait showed few differences. Our study also demonstrates that hatchery release strategies used near Taku Inlet successfully promote early spatial segregation and prey partitioning, which reduce the probability of competition between wild and hatchery chum salmon stocks.

High lacustrine gillnet catchability of anadromous Arctic charr

Arctic charr is the only freshwater fish in most of the High Arctic, with both resident, anadromous, and landlocked populations present. The anadromous Arctic charr is particularly highly sought-after, and has been an important food source for people living in Arctic regions. A recent decline in harvest in many areas has been related to over-exploitation by extensive gillnetting. Very few studies, if any, have estimated the gillnet efficiency for harvesting anadromous Arctic charr. In this study, all anadromous Arctic charr ascending the lake, Linnevatn, in western Spitsbergen, Svalbard, were marked over a period of 5 weeks, in July–August 2008. Recaptures in the lake were obtained by gillnetting with three mesh sizes (39, 45, and 52 mm measured knot-to-knot) during three periods. The total number of anadromous charr in the lake was estimated by both Schnabel and Petersen mark-recapture methods. The catchability increased significantly with fish size. Anadromous charr in the length-class 40.0–56.9 cm captured by the legal mesh size in Svalbard lakes (52 mm) had a mean catchability of 0.0023 per gillnet per 2 h fishing effort, and the catch quota which is set at 40 charr for Linnevatn by the Governor of Svalbard, would have been filled by less than five gillnets, each used for 6 h. Although this short fishing time may give an overestimation of catchability due to the avoidance of gear saturation, the high catchability values still indicate that anadromous Arctic charr populations may be extremely vulnerable to gillnetting. Hence, in addition to catch quotas set for each population, a restriction on the number of gillnets allowed per harvester should also be considered.

Winter Relative Abundance and Habitat Associations of Swamp Rabbits in Eastern Arkansas

Habitat loss coupled with decline in harvest has raised concern for Sylvilagus aquaticus (swamp rabbit) in Arkansas. We assessed relative abundance and habitat associations of swamp rabbits in eastern Arkansas using presence of latrine sites. We searched for fecal pellets at randomly chosen sites during winters 2002–03 and 2003–04. Swamp rabbits were detected at 85% and 76% of sites searched during years 1 and 2, respectively. Bignonia capreolata (crossvine) stem density was significantly greater at sites inhabited by swamp rabbits (mean = 625, SE = 141) than at uninhabited sites (mean = 0.00, SE = 0.00) in year 1, but no differences were found in year 2. We found no relationship between woodland tract size and pellet-group density. Logistic regression predicted presence of swamp rabbits 88.3% of the time based on crossvine density and percent ground cover of grasses. To understand the potential for conserving swamp rabbit populations in Arkansas, it will be necessary to assess remaining bottomland hardwood stands in relation to the quality of swamp rabbit habitat.

Inuvialuit Use of the Beaufort Sea and its Resources, 1960-2000

Comprehensive, census-type surveys of Inuvialuit harvesters were conducted in the Inuvialuit Settlement Region (ISR) in the 1960s (Area Economic Surveys) and 1970s (Inuit Land Use and Occupancy Project) and in the 1990s (Inuvialuit Harvest Study). These surveys, supplemented by other case studies, provide a basis for comparing Inuvialuit use of the Beaufort Sea and its resources in the 1960s and the 1990s. The geographic extent of harvesting was about the same in both decades. The number of harvesters grew, although by less than the rate of population growth. Mean annual harvest of country food per hunter declined from 2083 kg/yr to 707 kg/yr. The chief reason for the decline in harvest was the near-abandonment of dogs for transport. If we take into account the share of country food likely consumed by dogs, the per capita harvest of country food for human consumption may not have changed significantly between the two decades. What has changed, however, is the composition of the harvest: the ratio (by weight) of country foods from marine and terrestrial sources was 75:25 in the 1960s, but 45:55 in the 1990s. Available country food amounted to 115.2 kg/capita/yr in the 1990s, a significant contribution to the household economy. Thus, contrary to many predictions in the 1960s, subsistence harvesting persists as a significant economic as well as cultural preoccupation in the lives of Inuvialuit today. The results of this study suggest that the measurement of subsistence and commercial harvesting in terms of location, participation, inputs, and outputs is of continuing importance for fish and wildlife management and for economic planning.

Production and Harvest of Anadromous Striped Bass Stocks along the Atlantic Coast

Production indices for juvenile striped bass Morone saxatilis in the Chesapeake Bay and Roanoke River-Albemarle Sound regions have declined in recent years. A concurrent decline in harvest of striped bass along the Atlantic coast also has been observed. Lack of the occurrence of a dominant year class in the Chesapeake Bay since 1970 has affected the coastal harvest and the abundance of the spawning populations. Occurrence of another dominant year class will depend on two factors: Relatively good survival between the egg and juvenile life stages; and a sufficient amount of egg deposition to take advantage of the good survival conditions.