Strengthening community roles in aquatic resource governance in Uganda

Lake Victoria fisheries face severe environmental stresses. Stocks are declining in a context of increasing population and growing demand for the lake’s resources. Rising competition between users is putting conservation goals and rural livelihoods at risk. While Uganda’s co-management policy framework is well-developed, key resources for implementation are lacking, enforcement is poor, and the relations between stakeholders are unequal. Poor rural resource users face significant challenges to effectively participate in fisheries decision-making. This case study demonstrates the progress that can be made using a collaborative approach to catalyze community-led actions linking public health, sanitation and environmental conservation in difficult circumstances, even over a relatively short time period. Multistakeholder dialogue can bring to light the sources of conflict, pinpoint governance challenges, and identify opportunities for institutional collaboration to address community needs. At the same time, the process can help build trust, confidence in collective action and public accountability.

Climate-related long-term faunal changes in a California rocky intertidal community [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The effects of gradual climate change (ie, multi-decadal) on biological communities are not well understood for most natural systems, owing principally to the lack of quantitative observations in early studies. ... We resurveyed invertebrate species on an intertidal transect in central California, first established and surveyed in 1931, to assess shifts in community structure.

Zooplankton standing stock and community structure along Karnataka Coast, west coast of India

Distribution of zooplankton along two transects at Karwar and Ratnagiri, west coast of India, was studied. The standing stock of zooplankton was relatively high in the neritic zone with the highest value [358 ml/100 m super(3)] in the area off Ratnagiri due to the aggregation of fish larvae and hydromedusae. Maximum zooplankton production in these areas was noticed with the low temperature and low dissolved oxygen during postmonsoon season. At Karwar the highest biomass [188 ml/100 m super(3)] was observed from the nearshore station due to swarms of the cladoceran Penilia avirostris and the pteropod Cresis acicula when the salinity was low. The fluctuations in numerical abundance and percentage composition of all the major planktonic groups are discussed. The fishery of these areas is compared with the zooplankton standing stock.

Community metabolism, P/R ratio and photosynthetic efficiency of a brackishwater farm

The productivity level of a brackishwater fish culture farm consisting of 25 ponds, with a water spread area of 2.5 ha, was studied. Gross community photosynthesis of the farm was found to be 46.32 Kcal/m2/day, which is equivalent to the release of 13.23 of O2/m2/day, or the fixing of 4.10 gC/m2/day. Respiratory demand of the farm was estimated to be 44.66 kcal/m2/day, which is equivalent to the uptake of 12.76 g O2/m2/day or the utilization of 3.95 gC/m2/day. Photosynthetic efficiency of the farm was high at 2.26%. The P/R ratio was 1.04, showing eutrophic nature.

猪粪农用的生态风险——以东北黑土为例

集约化养殖大量使用铜(Cu)作为饲料添加剂会在养殖废物的排放和利用中导致一定的环境问题。随着东北老工业基地产业结构的调整，畜牧业作为东北地区二次振兴的主要产业得到迅速发展，由此会产生大量的畜禽粪便用于农业土壤施肥。而东北地区又是我国重要的农副产品生产基地，研究畜禽粪便农用的健康及环境风险就显得殊为必要。黑土是东北地区最主要的土壤类型，本文以东北黑土为供试材料，通过在盆栽实验中添加不同Cu浓度的猪粪来模拟施肥年限不同的菜园土，研究土壤中Cu累积对小白菜(Brassica chinensis L.)地上部分生物量与Cu含量、土壤微生物生物量和土壤酶(脱氢酶、脲酶、酸性磷酸酶)活性、微生物群落功能多样性以及对土壤功能微生物——氨氧化古菌(AOA)和氨氧化细菌(AOB)等的影响，从而实现含Cu猪粪农用对食物链途径的健康风险以及土壤生态系统的生态风险的综合评价。 研究结果表明，施用猪粪显著地改善了土壤的pH，增加了小白菜地上部分生物量，对其体内Cu浓度则没有显著影响;小白菜地上部分Cu浓度与土壤全Cu和水溶态Cu浓度显著正相关(P<0.01)，而地上生物量与土壤全Cu浓度显著负相关(P<0.05)。当土壤全Cu浓度达到300 mg kg-1后，小白菜地上部分生物量受到强烈抑制。 猪粪的施用在一定时期内显著地促进了脱氢酶和脲酶的活性，但随土壤Cu浓度的增加，脱氢酶、脲酶和酸性磷酸酶的活性逐渐受到抑制。当土壤全Cu浓度达到300 mg kg-1后，微生物生物量、脱氢酶、脲酶、酸性磷酸酶等均受到强烈抑制。 施加猪粪提高了土壤微生物群落功能多样性，当土壤Cu浓度达到170 mg kg-1后，显著地抑制了微生物群落功能多样性。种植小白菜后，各处理间微生物群落功能多样性没有显著差异，意味着植物能够维持微生物群落功能多样性。主成分分析(PCA)结果显示，当土壤全Cu浓度达到300 mg kg-1后，微生物群落功能多样性与其它处理显著不同。 猪粪显著地促进了土壤的硝化潜势速率(PNR)。随着Cu浓度的增加，硝化潜势速率逐渐受到抑制，当土壤全Cu浓度达到170 mg kg-1后，即与对照无显著差异。植物在维持硝化速率方面也起到重要作用。古菌amoA基因在每克干土中的拷贝数在9.4*106~2.59*107，细菌amoA基因在每克干土中的拷贝数约为1.48*106~1.41*107。猪粪在一定时期内显著地增加了AOA和AOB的数量，当土壤Cu浓度达到300 mg kg-1后，AOA和AOB的数量显著下降，并且AOA与AOB amoA基因拷贝数的比值增加，在小白菜栽种前(B1)和小白菜收获后(B2)分别为2.33和9.26，这意味着在高Cu浓度胁迫下，AOA的耐受性更强。古菌与细菌的amoA拷贝数与PNR之间则没有显著的相关关系，意味着AOA和AOB种群结构以及其中某些种群的活性可能发生了变化。 本文通过对东北黑土菜地土壤中Cu在作物体内的迁移积累及其对土壤微生物学指标(微生物生物量、酶活性、微生物群落功能多样性及功能微生物)的影响的综合研究，揭示了含Cu猪粪农用所造成的健康和生态风险，为建立适宜的土壤环境质量标准提供了一定的科学依据。通过本研究得出，黑土蔬菜种植中Cu浓度的阈值在170-300 mg kg-1之间。