We are saddened to have learned that Sidney J. Holt – one of the most influential fisheries scientists and marine conservationists of all time – has passed away at his home in Paciano, Italy, on 22 December 2019, at the respectable age of 93.

To anyone working in fisheries science, Sidney Holt is probably best known for the book that he and his great collaborator, Ray Beverton, jointly wrote during the immediate post‐war years at the Ministry of Agriculture and Fisheries laboratory in Lowestoft, UK. On the dynamics of exploited fish populations (Beverton & Holt, 1957) is still viewed as “the bible of fisheries science” by the majority of scientists working in this field. Not only has their book helped lay the foundations of fisheries science, it also covers early insights into a broad range of topics in fish biology and population ecology that are still discussed today. It is remarkable how young the two scientists were when they produced their master work: Sidney was only 21, and Ray 24, when they began their collaborative effort in 1947 (Anderson, 2011).

Building on earlier research (Baranov, 1918; Russell, 1931), Beverton and Holt developed the “yield‐per‐recruit equation” describing fisheries yield as a function of growth, recruitment, and natural and fishing mortality in fish populations. They developed what came to be known as the “Beverton‐Holt stock–recruitment relationship” now so widely used in fish stock assessment models. Their book introduced many other important concepts (Anderson, 2011): density dependence, trawl mesh selectivity, multispecies predator–prey interactions, marine reserves, fishing power and catching efficiency, to name but a few. Later on, the methods outlined and very clearly described by the two authors, led to the development of Virtual Population Analysis (VPA: Gulland, 1965), multispecies VPA (Sparre, 1991), extended survivors analysis (Shepherd, 1999) and indirectly, helped inspire a wide range of stock assessment models that are currently in use.

Sidney Holt is probably even more widely known for his important role beyond fisheries science – namely in the cessation of widespread, unsustainable commercial whaling. After he had begun working at the Food and Agriculture Organization (FAO), Rome, in 1953, he was invited by the International Whaling Commission (IWC) in 1960 to become one of the “Committee of Three”: a panel of three “independent” fisheries scientists, not specialized in whale assessment and not from countries engaged in Antarctic whaling, to provide advice on yields that would be sustainable. Based on their critical analysis, the panel's report in 1961 demonstrated that levels of whaling were unsustainable, had been so for decades, and that quotas had to be drastically reduced to allow whale populations to recover.

There was great resistance among whaling nations to reduce quotas and it took over two decades – during which time Sidney was a strong advocate of whale conservation – until an international moratorium on commercial whaling was agreed in 1982. In his article “Whale mining, whale saving”, Holt (1985) described vividly the enormous difficulties encountered by the IWC in obtaining agreement among all its member states. Throughout his lifetime, Sidney remained a vociferous ambassador for the plight of the great whales (e.g. Holt, 2000, 2002, 2003), continuing to write papers on the subject until he was well into his eighties: see, for example, his paper titled “Whaling: Will the Phoenix rise again?” in which he expressed his concerns about the possible re‐emergence of whaling, post‐moratorium (Holt, 2007).

In the past two decades, Sidney moved back to research and international management of marine fisheries, particularly in Europe concerning himself with the ongoing revision of the EU Common Fisheries Policy. In 2008, staff at the Lowestoft Laboratory, now known as the Centre for Environment, Fisheries & Aquaculture Science (Cefas), celebrated the legacy of the 1957 Beverton and Holt book with a special volume Advances in Fisheries Science: 50 years on from Beverton and Holt (Payne, Cotter, & Potter, 2008), which contains a foreword by Sidney, and chapters contributed by many younger scientists working at Cefas. Sidney came to Lowestoft for the book launch and gave an outstanding talk “Three lumps of coal: doing fisheries research in Lowestoft in the 1940s”, in which he vividly recalled how he and Ray Beverton, in a small and often chilly house adjacent to the laboratory (Figure 1), worked on the task given to them by Director Michael Graham of “putting the whole of this fish population stuff on a more substantial basis.”

In addition, Sidney showed great interest in the ICES Working Group on the History of Fish and Fisheries, for which he travelled to Ponza, Italy in 2010 and to Lowestoft in 2011; he even invited the Working Group to his home village in Umbria, Italy, where the meeting was held in 2013. While participating, many scientists of younger generations enjoyed discussing their work with Sidney, who was always highly engaged and contributed significantly through his encyclopaedic knowledge of fisheries and exploitation in the global policy arena. Several collaborative papers resulted (Engelhard et al., 2016; Holt & Raicevich, 2018). Sidney was very approachable; when one of us [GHE] gave a talk about fishing power in 2010, he remarked: “I thoroughly enjoyed your talk; not just because your analyses were based on North Sea plaice – a stock that is very close to my heart, that was central when Ray and I worked together in Lowestoft – but because it covered some really important topics that we should be working on more.”

In 2013, Sidney was selected as “Buckland Professor” by the Frank Buckland Foundation and on 1 March he gave the traditional “Buckland Lecture” in London's prestigious Fishmongers Hall, themed around the Reform of the Common Fisheries Policy. After capturing the audience by describing the “beauty of the Sigmoid Curve”, Sidney gave many arguments for fishing not at but somewhat below maximum sustainable yield (MSY). As he stated it, this “would not demand much sacrifice in terms of actual catch, but would provide catches of higher quality and stability (so, more valuable), for much less effort and hence be both more profitable and otherwise socially beneficial.” Sidney had been a vocal critic of using MSY as a target since the inception of this concept in the 1950s (Holt, 2015; Pauly, 2020).

In his long career, Sidney has served as professor or fellow at several universities. He authored or co‐authored more than 120 scientific papers, including 6 papers in Nature and 2 papers in Science. He received numerous awards for his contributions to science and conservation, particularly the Gold Medal of the WWF, the Global 500 Award of UNEP, the Royal Golden Ark of the Netherlands, and most recently in 2017 (and quite befittingly), the “Beverton Medal” of the Fisheries Society of the British Isles (FSBI) in its 50th anniversary year.

During his lifetime, Sidney Holt inspired multiple generations of fisheries scientists and conservationists across a wide range of different disciplines all around the globe.

He will be remembered as a radical scientist who regularly and repeatedly challenged orthodoxy, but also as the man who, as Ray Beverton stated it “saved the great whales in the early 1970s”; and as one of the founding fathers of fisheries science (Anderson, 2011): “a giant on whose shoulders we stand.”

我们很遗憾地得知，有史以来最有影响力的渔业科学家和海洋保护主义者之一的悉尼·霍尔特（Sidney J.Holt）于2019年12月22日在他位于意大利帕恰诺的家中去世，享年93岁。

对于任何从事渔业科学工作的人来说，西德尼·霍尔特（Sidney Holt）可能是他和他的伟大合作者雷·贝弗顿（Ray Beverton）在战后初期在英国洛斯托夫特（Lowestoft）的农业和渔业部实验室共同撰写的那本书。关于被开发鱼类种群的动态（Beverton＆Holt，1957年））仍被该领域的大多数科学家视为“渔业​​科学圣经”。他们的书不仅帮助奠定了渔业科学的基础，还涵盖了对鱼类生物学和种群生态学广泛主题的早期见解，而这些主题至今仍在讨论中。值得注意的是，两位科学家在完成自己的大师级作品时还很年轻：Sidney只有21岁，而Ray 24岁则是在1947年开始合作时（Anderson，2011年）。

Beverton和Holt在较早的研究（Baranov，1918； Russell，1931）的基础上，发展了“每产量产量方程”，该方程描述了渔业产量与鱼类种群的增长，补充，自然和捕捞死亡率的关系。他们建立了后来被广泛用于鱼类种群评估模型中的“贝弗顿－霍尔特种群与招聘关系”。他们的书介绍了许多其他重要概念（Anderson，2011年）：密度依赖性，拖网选择性，多物种捕食者与猎物之间的相互作用，海洋保护区，捕捞能力和捕捞效率等。后来，两位作者概述并非常清楚地描述了这些方法，从而导致了虚拟人口分析（VPA：Gulland，1965年），多物种VPA（Sparre，1991年），扩展的幸存者分析（Shepherd，1999年）和间接地，启发了当前正在使用的多种种群评估模型。

西德尼·霍尔特（Sidney Holt）可能以其在渔业科学之外的重要作用而广为人知，即在停止广泛的，不可持续的商业捕鲸方面。在1953年开始在罗马的粮食及农业组织（FAO）工作之后，他于1960年受国际捕鲸委员会（IWC）邀请，成为“三个委员会”之一：由三个“独立委员会”组成的小组并非专门从事鲸类评估的渔业科学家，也不来自从事南极捕鲸的国家的渔业科学家，就可持续的产量提出建议。根据他们的批判性分析，专家小组在1961年的报告中证明，捕鲸水平是不可持续的，几十年来一直如此，并且必须大幅度减少配额，以使鲸鱼种群得以恢复。

捕鲸国在减少配额方面遇到了很大的阻力，并且花了整整二十年的时间（在此期间，悉尼一直是鲸鱼养护的坚定倡导者）直到1982年达成国际暂停商业捕鲸的协议。在他的文章“捕鲸，节约鲸鱼”中霍尔特（Holt，1985）生动地描述了万国表在其所有成员国之间达成协议方面遇到的巨大困难。纵观他的一生，悉尼仍然是大鲸鱼的困境响亮的大使（如霍尔特，2000，2002，2003），继续撰写有关该主题的论文，直到他八十多岁为止：例如，参见他的题为“捕鲸：凤凰城会再次崛起吗？”的论文。在此期间，他对捕鲸后可能再次出现捕鲸表示关注（Holt，2007年）。

在过去的二十年中，Sidney回到海洋渔业的研究和国际管理领域，尤其是在欧洲，他对欧盟共同渔业政策的不断修订表示关注。2008年，Lowestoft实验室（现称为环境，渔业和水产养殖科学中心（Cefas））的工作人员特别纪念了1957年的Beverton and Holt著作的出版​​，以纪念渔业科学进展：距比弗顿和霍尔特（佩恩，科特和波特，2008年），其中包含Sidney的前言，以及由Cefas工作的许多年轻科学家提供的章节。席德尼（Sidney）来到洛斯托夫特（Lowestoft）进行本书的发布，并作了精彩演讲“三块煤：在1940年代在洛斯托夫特（Lowestoft）进行渔业研究”，他生动地回忆起他和雷·贝弗顿（Ray Beverton）在一个小而冷的房子里的样子。实验室（图1）完成了主任迈克尔·格雷厄姆（Michael Graham）赋予他们的任务，即“在更大的基础上充分考虑整个鱼类种群。”

此外，Sidney对ICES鱼类和渔业历史工作组表现出极大的兴趣，为此，他于2010年前往意大利Ponza和2011年前往Lowestoft；他甚至邀请工作组到2013年举行会议的意大利翁布里亚的家乡。参加会议时，许多年轻一代的科学家都喜欢与Sidney讨论他们的工作，Sidney一直很投入，并通过他的百科全书知识做出了重要贡献全球政策领域的渔业和剥削。结果产生了几篇合作论文（Engelhard等，2016 ; Holt＆Raicevich，2018）。悉尼很平易近人。当我们中的一位[GHE]在2010年发表关于捕鱼能力的演讲时，他说：“我非常喜欢您的演讲；不仅是因为您的分析是基于北海虫（一种非常贴近我的股票，当雷和我在Lowestoft合作时是至关重要的），而且还因为它涵盖了一些我们应该进一步研究的非常重要的话题。 ”

2013年，西德尼（Sidney）被弗兰克·巴克兰基金会（Frank Buckland Foundation）选为“巴克兰教授”，并于3月1日在伦敦享有盛名的鱼贩大厅举行了以“共同渔业政策改革”为主题的传统“巴克兰演讲”。在通过描述“ Sigmoid曲线的美”吸引了观众之后，Sidney提出了许多论点，即捕鱼的渔获率不低于最大可持续产量（MSY）。正如他所说的那样，“这不会要求在实际捕捞量上付出太多的牺牲，而是会以更少的工作量提供更高质量和稳定性（因此，更有价值）的捕捞量，从而既有利可图又有利于社会。” 自1950年代提出这个概念以来，Sidney一直批评使用MSY作为目标（Holt，2015； Pauly，2020）。

在他漫长的职业生涯中，Sidney曾在几所大学担任教授或研究员。他撰写或合着了120多篇科学论文，包括《自然》杂志的6篇论文和《科学》杂志的2篇论文。他因对科学和自然保护的贡献而获得了无数奖项，特别是世界自然基金会的金奖，环境署的全球500强奖，荷兰的皇家金方舟，最近一次是在2017年（而且非常合适），“贝弗顿奖章”是不列颠群岛渔业协会（FSBI）成立50周年。

席德尼·霍尔特（Sidney Holt）在他的一生中启发了全球范围内不同学科的多代渔业科学家和保护主义者。

人们会记得他是一位激进的科学家，经常和反复地挑战正统观念，但也被铭记为雷·贝弗顿（Ray Beverton）所说的“在1970年代初拯救了大鲸鱼”的人。作为渔业科学的奠基人之一（安德森，2011年）：“我们站在肩膀上的巨人。”