Reported retained annual catch from Commonwealth fisheries logbooks

##Description\r\nWhile at sea, Commonwealth fishers must record all catch and effort in their AFMA daily fishing logbooks. This dataset shows the annual retained catch (meaning the catch that is not returned to the sea) in kilograms, by species and fishery, for Commonwealth fisheries managed by the Australian Fisheries Management Authority (AFMA). \r\nThese data are sourced from AFMA daily fishing logbooks, which fishers complete while at sea, where generally the weights are estimates only. Fish discarded at sea are not included in this dataset. Location of catches within a fishery is not included.\r\n\r\n##Appropriate use and limitations of the data\r\nThe catch weight data in logbooks are estimates only, which have been recorded by fishers while at sea. Fishers usually cannot accurately weigh fish at sea, so the estimated weights are mostly based on volume (i.e. the size and number of boxes of fish caught). Catch data are used in combination with gear, effort, and spatial data to inform stock assessments.\r\nThese data may differ from other summations over the same time period (such as stock assessment reports) due to differences in data handling procedures. For example, scientists may filter out catches from their assessments because of data quality issues or group species differently. In addition, the data may be different in other datasets with different summations such as catch by season or catch from the date fish were landed at port.\r\nCare should be taken when interpreting trends in this data because there are many factors that can affect catches each year. Catch quantities can be impacted by management measures such as: total allowable catch, closures of fishing areas, reducing boat numbers, or banning the catch of a particular species. Similarly, changes in market demand can affect which species are targeted. \r\nWhen the fish are landed at port, the accurate weight of fish is recorded in AFMA catch disposal records by both the fisher and fish receiver permit holder. This information can be found in the “Reported landed annual catch from Commonwealth fisheries catch disposal records” and its metadata, which is published on data.gov.au. \r\n\r\n##Disclaimer\r\nThe dataset provided by AFMA is comprised of raw (unprocessed) data as received from fishers, and may contain errors or be incomplete. Errors are more likely in the species caught in low volumes. AFMA makes no warranty or representation that the data is accurate or complete. Those who choose to use this data should make their own enquiries as to its accuracy and completeness, and AFMA assumes no liability for any errors or omissions in the data provided, or for any decision by a person who chooses to rely on the data.\r\n

## 数据集描述
在海上作业期间，澳大利亚联邦渔民需将所有捕捞作业与渔获情况记录于澳大利亚渔业管理局（Australian Fisheries Management Authority，AFMA）的每日捕捞日志中。本数据集展示了由AFMA管理的澳大利亚联邦渔业的年度保留渔获量（指未被放回海洋的渔获），按物种与捕捞作业类型分类，单位为千克。
本数据集的数据来源于渔民海上填写的AFMA每日捕捞日志，其中的重量信息通常仅为估算值。本数据集不包含海上丢弃的渔获，也未记录某一捕捞作业内的具体渔获位置。

## 数据的合理使用与局限性
日志中的捕捞重量数据仅为渔民海上记录的估算值。由于渔民通常无法在海上准确称量渔获，因此估算重量大多基于捕捞渔获的体积（即渔获箱的尺寸与数量）。捕捞数据将与渔具信息、捕捞努力量及空间数据结合，用于渔业种群评估。
由于数据处理流程存在差异，本数据集与同期其他汇总数据（如种群评估报告）可能存在出入。例如，科研人员可能因数据质量问题在评估中剔除部分捕捞数据，或对物种进行不同的归类。此外，本数据集与其他采用不同汇总方式的数据集（如按季节汇总的捕捞数据、按渔获上岸日期汇总的捕捞数据）也可能存在差异。
解读本数据集的年度趋势时需谨慎，因为每年的渔获量受诸多因素影响。捕捞数量可能受到多项管理措施的影响，例如总允许捕捞量、捕捞区域禁渔、缩减作业船只数量，或禁止捕捞特定物种。同理，市场需求的变化也会影响目标捕捞物种的选择。
当渔获被运抵港口时，渔民与渔获接收许可持有人会将准确的渔获重量记录在AFMA的渔获处置记录中。该信息可在data.gov.au发布的《澳大利亚联邦渔业渔获处置记录上报年度上岸渔获量》（Reported landed annual catch from Commonwealth fisheries catch disposal records）及其元数据中查询获取。

## 免责声明
AFMA提供的本数据集为直接从渔民处获取的原始（未经过处理）数据，可能存在错误或信息不完整的情况。低捕获量的物种相关数据更易出现误差。AFMA不对本数据集的准确性与完整性作出任何担保或声明。使用本数据集的用户应自行核实数据的准确性与完整性，AFMA不对所提供数据中的任何错误、遗漏，或因用户依赖该数据作出决策而导致的任何后果承担责任。