Communicating climate change and biodiversity loss with local populations: exploring communicative utopias in eight transdisciplinary case studies.

Climate change and biodiversity loss trigger policies targeting and impacting local communities worldwide. However, research and policy implementation often fail to sufficiently consider community responses and to involve them. We present the results of a collective self-assessment exercise for eight case studies of communications with regard to climate change or biodiversity loss between project teams and local communities. We develop eight indicators of good stakeholder communication, reflecting the scope of Verran's (2002) concept of postcolonial moments as a communicative utopia. We demonstrate that applying our indicators can enhance communication and enable community responses. However, we discover a divergence between timing, complexity and (introspective) effort. Three cases qualify for postcolonial moments, but scrutinising power relations and genuine knowledge co-production remain rare. While we verify the potency of various instruments for deconstructing science, their sophistication cannot substitute trust building and epistemic/transdisciplinary awareness. Lastly, we consider that reforming inadequate funding policies helps improving the work in and with local communities.

Are there any effects of eco-climatic factors on freshwater prawn reproduction: a study on monsoon river prawn, Macrobrachium malcolmsonii.

Prawns are regarded as delicious food items and a source of income as it is the salient exportable fishery item of Bangladesh and a number of other countries. Climate change may inhibit the general physiological activity of prawns. This study explored the eco-climatic effects on reproduction, including size at first sexual maturity (Lm), spawning season, and fecundity of monsoon river prawn, Macrobrachium malcolmsonii (Milne-Edwards, 1844). The study was carried out in the Ganges (Padma) River basin, northwestern Bangladesh, from January to December 2014. Seven hundred fifty-seven specimens ranging from 0.80 to 18.27 g BW (body weight) with TLs (total length) of 4.20 to 11.52 cm were analyzed. The Lm was estimated as 6.2-6.6 cm. Total fecundity was higher than earlier studies and ranged from 2743 to 122,165 with a mean value of 6715 ± 2437. The spawning season was estimated from April to October with a peak in July. Significant correlation was found between rainfall and the presence of ovigerous females, i.e., spawning season. The number of ovigerous females increased in ≥ 100 mm average rainfall, and the maximum ovigerous female spawned at 250-320 mm rainfall. Spawning season of M. malcolmsonii may have shifted with shifting rainy season as a result of climate change. The findings of our investigation would be useful for sustainable management of the fishery of M. malcolmsonii and other prawn species in the Ganges River, Bangladesh, and adjoining countries with similar eco-climatic factors.

Reproductive biology of Heteropneustes fossilis in a wetland ecosystem (Gajner Beel, Bangladesh) in relation to eco-climatic factors: Suggesting a sustainable policy for aquaculture, management and conservation.

The stinging catfish, Heteropneustes fossilis (Bloch, 1974) is a commercially important fish species in Asia. This is an important food fish as is enriched with high amounts of protein, iron and calcium. The current research demonstrates the population structure, size at sexual maturity, spawning- and peak-spawning season and fecundity of H. fossilis in an important wetland ecosystem - Gajner Beel in northwestern Bangladesh with an aim of its sustainable conservation through induced breeding and aquaculture practices. A total of 426 stinging catfish captured from the Gajner Beel through monthly sampling from January to December 2019 used in the study. Total length (TL), standard length (SL) and body weight (BW) of individual fishes were measured. The size ranges were with 6.70-24.10 cm TL, 1.37-83.94 g BW. Gonads were removed carefully through ventral dissection and weighted. Lm was 14.02, 13.5, 13.0 and 15.0 cm based on maximum length (Lmax ), TL vs. GSI (%), TL vs. SL and logistic model, respectively. Monthly variations of GSI and maturation stages were confirmed in April to August as spawning season and June as peak spawning month. Fulton's condition factor (KF ) was found to be with significant relations with GSI values. Fecundity was 1,730 to 23,870 and significantly correlated with both TL and BW. Temperature has been increasing 0.029 °C/year with the falling of rainfall at 2.96 mm/year in the study area. Environmental factors -Temperature, rainfall, dissolved oxygen and pH were found to be significantly correlated with GSI. We found the optimal range of temperature (29-31 °C), rainfall (350-380 mm), dissolved oxygen (5.0-6.0 mg/l) and pH (7.1-7.5) for spawning of H. fossilis. The paper recommended the policy guidelines to pave the ways of the aquaculture, conservation and management of H. fossilis in the changing eco-climatic events through specific management measures.

Characterization of the complete mitochondrial genome of Gangetic ailia, Ailia coila (Siluriformes: Ailiidae).

The first complete mitochondrial genome sequence of Ailia coila from Bangladesh was determined by the bioinformatic assembly of the next generation sequencing (NGS) reads. The constructed circular mitogenome for A. coila was 16,565 bp in length which harbored the canonical 13 protein-coding genes, 22 tRNAs, 2 rRNAs. Two non-coding regions, control region, D-loop (927 bp), and origin of light strand replication, OL (30 bp) were also well conserved in the mitogenome. Among the currently reported mitochondrial genomes in the order Siluriformes, A. coila was most closely related to Eutropiichthys vacha (AB919123) with 85.63% sequence identity.

Biology and fisheries of Hilsa shad in Bay of Bengal.

Hilsa (Tenualosa ilisha) or river shad is an anadromous fish species widely distributed in the North Indian Ocean, mainly in the Bay of Bengal (BoB). Hilsa is the national fish of Bangladesh and it contributes 10% of the total fish production of the country, with a market value of $1.74 billion. Hilsa also holds a very important place in the economics of West Bengal of India with 12.5% of the catch and also tops the marine capture in Myanmar. During the last two decades Hilsa production from inland waters has been stable, whereas marine yields in the BoB increased substantially. In order to sustainably manage the trans-boundary stock of Hilsa, the taxonomy, distribution, habitat, migration patterns, population dynamics, fisheries and socio-economics aspects of the fishery have been reviewed here. To achieve a successful trans-boundary management for the Hilsa stock, complete ban on undersize fishing, well-targeted temporal and spatial bans, creation of protected areas in strategic points, incentive for Hilsa fishers and ecological restoration of Hilsa habitats and more work on technological development of Hilsa aquaculture are recommended.

Importance of fisheries for food security across three climate change vulnerable deltas.

Deltas are home to a large and growing proportion of the world's population, often living in conditions of extreme poverty. Deltaic ecosystems are ecologically significant as they support high biodiversity and a variety of fisheries, however these coastal environments are extremely vulnerable to climate change. The Ganges-Brahmaputra-Meghna (Bangladesh/India), the Mahanadi (India), and the Volta (Ghana) are among the most important and populous delta regions in the world and they are all considered at risk of food insecurity and climate change. The fisheries sector is vital for populations that live in the three deltas, as a source of animal protein (in Bangladesh and Ghana around 50-60% of animal protein is supplied by fish while in India this is about 12%) through subsistence fishing, as a source of employment and for the wider economy. The aquaculture sector shows a rapid growth in Bangladesh and India while in Ghana this is just starting to expand. The main exported species differ across countries with Ghana and India dominated by marine fish species, whereas Bangladesh exports shrimps and prawns. Fisheries play a more important part in the economy of Bangladesh and Ghana than for India, both men and women work in fisheries, with a higher proportion of women in the Volta then in the Asian deltas. Economic and integrated modelling using future scenarios suggest that changes in temperature and primary production could reduce fish productivity and fisheries income especially in the Volta and Bangladesh deltas, however these losses could be mitigated by reducing overfishing and improving management. The analysis provided in this paper highlights the importance of applying plans for fisheries management at regional level. Minimizing the impacts of climate change while increasing marine ecosystems resilience must be a priority for scientists and governments before these have dramatic impacts on millions of people's lives.

Impacts and responses to environmental change in coastal livelihoods of south-west Bangladesh.

Aquatic ecosystems are of global importance for maintaining high levels of biodiversity and ecosystem services, and for the number of livelihoods dependent on them. In Bangladesh, coastal and delta communities rely on these systems for a livelihood, and the sustainability of the productivity is seriously threatened by both climate change and unsustainable management. These multiple drivers of change shape the livelihood dependence and adaptation responses, where a better understanding is needed to achieve sustainable management in these systems, while maintaining and improving dependent livelihoods. This need has been addressed in this study in the region of Satkhira, in the southwest coast of Bangladesh, where livelihoods are highly dependent on aquatic systems for food supply and income. Traditional wild fish harvest in the rivers and aquaculture systems, including ghers, ponds, and crab points have been changing in terms of the uses and intensity of management, and suffering from climate change impacts as well. By means of six focus groups with 50 participants total, and validated by expert consultations, we conduct an analysis to understand the main perceived impacts from climate and human activities; and the adaptation responses from the aquatic system livelihoods. We find that biodiversity has decreased drastically, while farmed species have increased and shrimp gher farming turned more intensive becoming the main source of income. All these changes have important implications for food supply in the region and environmental sustainability. Dramatic responses taken in the communities include exit the fisheries and migration, and more adaptive responses include species diversification, crab fattening and working more on the pond and gher infrastructure. This study evidences the results of the combination of multiple stressors in productive systems and the barriers to adaptation in aquatic ecosystem dependent communities.

Sperm cryopreservation of the critically endangered olive barb (Sarpunti) Puntiussarana (Hamilton, 1822).

The present study focused on development of a sperm cryopreservation protocol for the critically endangered olive barb Puntiussarana (Hamilton, 1822) collected from two stocks within Bangladesh and reared in the Fisheries Field Laboratory, Bangladesh Agricultural University (BAU). The sperm were collected in Alsever's solution prepared at 296mOsmol kg(-1). Sperm were activated with distilled water (24mOsmol kg(-1)) to characterize motility. Maximum motility (90%) was observed within 15s after activation, and sperm remained motile for 35s. Sperm activation was evaluated in different osmolalities and motility was completely inhibited when osmolality of the extender was ≥287mOsmol kg(-1). To evaluate cryoprotectant toxicity, sperm were equilibrated with 5%, 10% and 15% each of dimethyl sulfoxide (DMSO) and methanol. Sperm motility was noticeably reduced within 10min, when sperm were equilibrated with 15% DMSO, indicating acute toxicity to spermatozoa and therefore this concentration was excluded in further trials. Sperm were cryopreserved using DMSO at concentrations of 5% and 10% and methanol at 5%, 10% and 15%. The one-step freezing protocol (from 5°C to -80°C at 10°C/min) was carried out in a computer-controlled freezer (FREEZE CONTROL® CL-3300; Australia) and 0.25-ml straws containing spermatozoa were stored in liquid nitrogen for 7-15days at -196°C. The highest motility in thawed sperm 61±8% (mean±SD) was obtained with 10% DMSO. The fertilization and hatching rates were 70% and 37% for cryopreserved sperm, and 72% and 62% for fresh sperm. The protocol reported here can be useful for hatchery-scale production of olive barb. The use of cryopreserved sperm can facilitate hatchery operations, and can provide for long-term conservation of genetic resources to contribute in the recovery of critically endangered fish such as the olive barb.