Trifurcated Discovery: 1) size-at-age in exploited fish, 2) biomass spectrum in Northumberland Strait, and 3) finalising particle dispersion.

三叉发现：1）所开发鱼类的年龄大小，2）诺森伯兰海峡的生物量谱，以及3）最终确定颗粒分散。

• 批准号: RGPIN-2014-04036
• 负责人: Taggart, Christopher
• 金额: $ 1.75万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=566255
• 关键词: Trifurcated; Discovery; size; age; exploited

The proposal has 3 parts. First, is working with a student on a relatively new measure of ocean temperature and its relation to fish growth. It is the growing degree day metric (GGD) or thermal integral; a sum of heat transferred from the ocean to a fish. Fish are cold-blooded. More heat means better physiological functioning and larger size-at-age. Size-at-age is a growth integral. Thus, we expect a relation between the growth and thermal integrals. Recent work with a student shows this is precisely what we observe. Other researchers have now adopted the metric to examine various aspects of fish physiology. The metric is the one farmers use to determine crop ripening, but they use air temperature. We will expand our use of the metric across a suite of commercially valuable fish species because we have also shown that the GDD can be used to diagnose species and stocks that might be suffering from size-selective fishing. If a fishery preferentially targets the large fish, it is catching the fish that grow the fastest and mature the latest (maturation causes growth slow down). If this happens then the majority of the fish in the stock are smaller than they used to be at a given age, and they mature earlier. Also, when a stock suffers size-selective effects it becomes less sustainable. Smaller fish produce fewer eggs and the earlier maturing fish have less viable eggs and larvae. Increased evidence of the effects has raised concerns that they may be irreversible. We do know it becomes more difficult for a stock to replace itself. Thus fishing becomes less sustainable. If we can diagnose stocks showing size-selective effects, we can address pressing issues related to sustainable fisheries management, including recruitment (new fish) and changes in ecosystem structure, function and species diversity. We know the effects of unsustainable fishing, e.g., Canadian cod stocks, but now there is a selective fishing concern that the student and I, and a group of colleagues, wish to address before the consequences become apparent. Second, is working with a student and colleagues with similar interests to determine if the zooplankton (small crustaceans or sea fleas) biomass spectrum is a suitable measure of the functioning of the Northumberland Strait ecosystem. The biomass spectrum is a size-based measure of how much energy (e.g., calories) is in a body of water and how the energy varies in time and space when transferred through the food web from smaller to larger organisms such as fish, crabs and lobster that are critical ecological components of the Strait and represent a valuable fishery. The utility of the spectrum lies in its species independence that simplifies what would be more difficult from a species perspective. The value of studying the Strait is that it is somewhat like a pipe. It has inflow at one end of the Strait and outflow at the other, with known estuarine nutrient-input along the way. This simplifies what would be difficult and expensive to do the open ocean. If we show that the spectrum is suitable, then its utility becomes readily apparent to those involved in marine modeling and conservation interests such as integrated ecosystem management and the design of marine protected areas. Third, I wish to complete research with a student on our recently developed particle tracing technology to estimate early life-stage dispersal (transport and spreading) of aquatic organisms that is essential for explaining the connectivity of marine species. The technology, first of its kind, allows us to measure dispersal with real particles of the same size and buoyancy as biological particles (e.g., eggs and larvae). The research also contributes to improving numerical ocean models that struggle with small-scale diffusion processes.

该提案有3个部分。首先，正在与学生合作采用相对较新的海洋温度量度及其与鱼类生长的关系。它是增长的度量日度量（GGD）或热积分；从海洋传递到鱼的热量。鱼是冷血的。更多的热量意味着更好的生理功能和更大的年龄。大小年龄是一个增长积分。因此，我们期望生长和热积分之间存在关系。与学生的最新工作表明，这正是我们观察到的。现在，其他研究人员已经采用了该指标来检查鱼类生理的各个方面。度量标准是农民用来确定作物成熟的人，但他们使用空气温度。我们将扩大对商业有价值的鱼类套件的使用，因为我们还表明，GDD可用于诊断可能患有大小选择性捕鱼的物种和种群。如果渔业优先针对大鱼，它正在捕获最新生长和成熟的鱼（成熟会导致生长速度减慢）。如果发生这种情况，那么库存中的大多数鱼都比以前在给定年龄的年龄要小，并且它们早于成熟。同样，当股票遭受尺寸选择性效果时，它会变得不那么可持续。较小的鱼产生的鸡蛋较少，而早期的成熟鱼的卵子和幼虫的卵较少。越来越多的证据引起了人们对它们可能不可逆转的担忧。我们确实知道，股票更换自身变得更加困难。因此，捕鱼变得不那么可持续。如果我们可以诊断出显示大小选择效果的库存，我们可以解决与可持续渔业管理有关的紧迫问题，包括招募（新鱼）和生态系统结构，功能和物种多样性的变化。我们知道不可持续的捕鱼的影响，例如加拿大鳕鱼库存，但是现在有选择性的捕鱼问题，即学生和我以及一群同事希望在后果显而易见。其次，正在与具有相似兴趣的学生和同事一起确定浮游动物（小型甲壳类或海跳蚤）生物量谱系是诺森伯兰海峡生态系统功能的合适度量。生物质谱是一种基于尺寸的度量，以衡量水体中有多少能量（例如卡路里），以及通过食物网通过食物网传递从较小的生物到较大的生物（如鱼类，螃蟹和龙虾）（例如关键的海峡生态成分）时，能量在时空中如何变化。频谱的效用在于其物种独立性，从物种的角度简化了更加困难的东西。研究海峡的价值在于它有点像管道。它在海峡的一端有流入，另一端流出，沿途有已知的河口营养素输入。这简化了开放海洋的困难和昂贵的东西。如果我们证明频谱是合适的，那么对于参与海洋建模和保护兴趣的人，例如综合生态系统管理和海洋保护区的设计，其效用很容易就显而易见。第三，我希望与学生对我们最近开发的粒子追踪技术进行研究，以估算水生生物的早期生命阶段分散（运输和扩散），这对于解释海洋物种的连通性至关重要。该技术首先使我们能够测量与生物颗粒（例如卵子和幼虫）相同大小和浮力的真实颗粒的分散。这项研究还有助于改善与小规模扩散过程斗争的数值海洋模型。