Ruth H. Thurstan

The effects of 118 years of industrial fishing on UK bottom trawl fisheries

In 2009, the European Commission estimated that 88% of monitored marine fish stocks were overfished, on the basis of data that go back 20 to 40 years and depending on the species investigated. However, commercial sea fishing goes back centuries, calling into question the validity of management conclusions drawn from recent data. We compiled statistics of annual demersal fish landings from bottom trawl catches landing in England and Wales dating back to 1889, using previously neglected UK Government data. We then corrected the figures for increases in fishing power over time and a recent shift in the proportion of fish landed abroad to estimate the change in landings per unit of fishing power (LPUP), a measure of the commercial productivity of fisheries. LPUP reduced by 94%-17-fold--over the past 118 years. This implies an extraordinary decline in the availability of bottom-living fish and a profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing.

Ecological meltdown in the Firth of Clyde, Scotland: two centuries of change in a coastal marine ecosystem.

Background The Firth of Clyde is a large inlet of the sea that extends over 100 km into Scotlands west coast. Methods We compiled detailed fisheries landings data for this area and combined them with historical accounts to build a picture of change due to fishing activity over the last 200 years. Findings In the early 19th century, prior to the onset of industrial fishing, the Firth of Clyde supported diverse and productive fisheries for species such as herring (Clupea harengus, Clupeidae), cod (Gadus morhua, Gadidae), haddock (Melanogrammus aeglefinus, Gadidae), turbot (Psetta maxima, Scophthalmidae) and flounder (Platichthys flesus, Pleuronectidae). The 19th century saw increased demand for fish, which encouraged more indiscriminate methods of fishing such as bottom trawling. During the 1880s, fish landings began to decline, and upon the recommendation of local fishers and scientists, the Firth of Clyde was closed to large trawling vessels in 1889. This closure remained in place until 1962 when bottom trawling for Norway lobster (Nephrops norvegicus, Nephropidae) was approved in areas more than three nautical miles from the coast. During the 1960s and 1970s, landings of bottomfish increased as trawling intensified. The trawl closure within three nautical miles of the coast was repealed in 1984 under pressure from the industry. Thereafter, bottomfish landings went into terminal decline, with all species collapsing to zero or near zero landings by the early 21st century. Herring fisheries collapsed in the 1970s as more efficient mid-water trawls and fish finders were introduced, while a fishery for mid-water saithe (Pollachius virens, Gadidae) underwent a boom and bust shortly after discovery in the late 1960s. The only commercial fisheries that remain today are for Nephrops and scallops (Pecten maximus, Pectinidae). Significance The Firth of Clyde is a marine ecosystem nearing the endpoint of overfishing, a time when no species remain that are capable of sustaining commercial catches. The evidence suggests that trawl closures helped maintain productive fisheries through the mid-20th century, and their reopening precipitated collapse of bottomfish stocks. We argue that continued intensive bottom trawling for Nephrops with fine mesh nets will prevent the recovery of other species. This once diverse and highly productive environment will only be restored if trawl closures or other protected areas are re-introduced. The Firth of Clyde represents at a small scale a process that is occurring ocean-wide today, and its experience serves as a warning to others.

The past and future of fish consumption: can supplies meet healthy eating recommendations?

In many developed countries fish and shellfish are increasingly promoted as healthy alternatives to other animal protein. We analysed how much fish was available to UK and global populations after accounting for processing losses, and compared this to recommended levels of fish consumption. In 2012, UK domestic fish landings per capita fell 81% below the recommended intake, although declines were masked by increased imports and aquaculture from the 1970s onwards. Global wild fish supply per capita declined by 32% from its peak in 1970. However, overall fish supplies per capita increased by 10% over the same period due to rapidly expanding aquaculture production. Whilst aquaculture has so far prevented a downturn in global fish supplies, many developed nations continue to aspire to consume more fish than they produce. Until demand is balanced with sustainable methods of production governments should consider carefully the social and environmental implications of greater fish consumption.

A Citizen Science Approach: A Detailed Ecological Assessment of Subtropical Reefs at Point Lookout, Australia

Subtropical reefs provide an important habitat for flora and fauna, and proper monitoring is required for conservation. Monitoring these exposed and submerged reefs is challenging and available resources are limited. Citizen science is increasing in momentum, as an applied research tool and in the variety of monitoring approaches adopted. This paper aims to demonstrate an ecological assessment and mapping approach that incorporates both top-down (volunteer marine scientists) and bottom-up (divers/community) engagement aspects of citizen science, applied at a subtropical reef at Point Lookout, Southeast Queensland, Australia. Marine scientists trained fifty citizen scientists in survey techniques that included mapping of habitat features, recording of substrate, fish and invertebrate composition, and quantifying impacts (e.g., occurrence of substrate damage, presence of litter). In 2014 these volunteers conducted four seasonal surveys along semi-permanent transects, at five sites, across three reefs. The project presented is a model on how citizen science can be conducted in a marine environment through collaboration of volunteer researchers, non-researchers and local marine authorities. Significant differences in coral and algal cover were observed among the three sites, while fluctuations in algal cover were also observed seasonally. Differences in fish assemblages were apparent among sites and seasons, with subtropical fish groups observed more commonly in colder seasons. The least physical damage occurred in the most exposed sites (Flat Rock) within the highly protected marine park zones. The broad range of data collected through this top-down/bottom-up approach to citizen science exemplifies the projects’ value and application for identifying ecosystem trends or patterns. The results of the project support natural resource and marine park management, providing a valuable contribution to existing scientific knowledge and the conservation of local reefs.

Historical spatial reconstruction of a spawning-aggregation fishery

Aggregations of individual animals that form for breeding purposes are a critical ecological process for many species, yet these aggregations are inherently vulnerable to exploitation. Studies of the decline of exploited populations that form breeding aggregations tend to focus on catch rate and thus often overlook reductions in geographic range. We tested the hypothesis that catch rate and site occupancy of exploited fish-spawning aggregations (FSAs) decline in synchrony over time. We used the Spanish mackerel (Scomberomorus commerson) spawning-aggregation fishery in the Great Barrier Reef as a case study. Data were compiled from historical newspaper archives, fisher knowledge, and contemporary fishery logbooks to reconstruct catch rates and exploitation trends from the inception of the fishery. Our fine-scale analysis of catch and effort data spanned 103 years (1911-2013) and revealed a spatial expansion of fishing effort. Effort shifted offshore at a rate of 9.4 nm/decade, and 2.9 newly targeted FSAs were reported/decade. Spatial expansion of effort masked the sequential exploitation, commercial extinction, and loss of 70% of exploited FSAs. After standardizing for improvements in technological innovations, average catch rates declined by 90.5% from 1934 to 2011 (from 119.4 to 11.41 fish/vessel/trip). Mean catch rate of Spanish mackerel and occupancy of exploited mackerel FSAs were not significantly related. Our study revealed a special kind of shifting spatial baseline in which a contraction in exploited FSAs occurred undetected. Knowledge of temporally and spatially explicit information on FSAs can be relevant for the conservation and management of FSA species.

Popular media records reveal multi-decadal trends in recreational fishing catch rates

Despite threats to human wellbeing from ecological degradation, public engagement with this issue remains at low levels. However, studies have shown that crafting messages to resonate with people’s personal experiences can enhance engagement. Recreational fishing is one of the principal ways in which people interact with aquatic environments, but long-term data from this perspective are considered rare. We uncovered 852 popular media records of recreational fishing for an Australian estuary across a 140-year period. Using information contained in these articles we analysed the species composition of recreational catches over time and constructed two distinct time series of catch and effort (n fish fisher-1 trip-1; kg fish fisher-1 trip-1) for recreational fishing trips and fishing club competitions (mean n and kg fish caught across all competitors, and n and kg fish caught by the competition winner). Reported species composition remained similar over time. Catch rates reported from recreational fishing trips (1900–1998) displayed a significant decline, averaging 32.5 fish fisher-1 trip-1 prior to 1960, and 18.8 fish fisher-1 trip-1 post-1960. Mean n fish fisher-1 competition-1 (1913–1983) also significantly declined, but best n fish fisher-1 competition-1 (1925–1980) displayed no significant change, averaging 31.2 fish fisher-1 competition-1 over the time series. Mean and best kg fish fisher-1 competition-1 trends also displayed no significant change, averaging 4.2 and 9.9 kg fisher-1 competition-1, respectively. These variable trends suggest that while some fishers experienced diminishing returns in this region over the last few decades, the most skilled inshore fishers were able to maintain their catch rates, highlighting the difficulties inherent in crafting conservation messages that will resonate with all sections of a community. Despite these challenges, this research demonstrates that popular media sources can provide multiple long-term trends at spatial scales, in units and via a recreational experience that many people can relate to.

Acknowledging Long-Term Ecological Change: The Problem of Shifting Baselines

Shifting baselines describes the phenomenon where long-term changes to an environment go unrecognized because what is perceived as natural shifts with succeeding generations of scientists and other observers. This is a particular problem for the oceans because we are rarely able to directly observe the consequences of human activities. In the absence of data to track these consequences, a common assumption has been that the communities we observe today using SCUBA or other technology, are similar to the communities that existed 10, 100, or even 1000 years ago. Research is increasingly demonstrating this is not the case. Instead, marine ecosystems may have been vastly different in the past, and we have succumbed to the shifting baselines syndrome. This has significant implications for scientific study, management, and for human communities more broadly. We discuss these implications, and how we might address the shifting baseline syndrome in the oceans to confront its repercussions. In a world where environmental degradation is accelerating, doing so is critical to avoid further ratcheting down of our expectations of ecosystem health and productivity, and to ensure that we have the information necessary to implement appropriate recovery and management goals.

Oral Histories: Informing Natural Resource Management Using Perceptions of the Past

In a rapidly changing world, oral history – a recorded dialogue between an interviewer and interviewee – is becoming an increasingly valued method by which to describe past marine environments and to enhance our knowledge of ecological changes. Using case studies from the 1860s to the present day we demonstrate the important role that oral history plays in providing novel information for science and natural resource management: from testimonies of changes in fish size and abundance to descriptions of local environmental change. Whilst the interpretation and application of such research presents many challenges for resource management, the narratives that stem from oral history can often hold much greater meaning to the public or local stakeholders than scientific observations alone. Thus, oral history not only has an important role to play in filling knowledge gaps but also may help to generate greater acceptance of the magnitude of change being observed in marine environments.

Stakeholder perceptions of a coastal marine protected area

ABSTRACT Clarke, B.; Thurstan, R.H.; and Yates, K.L, 2016. Stakeholder perceptions of a coastal marine protected area, . In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 622–626. Coconut Creek (Florida), ISSN 0749-0208. Marine protected areas (MPAs) are an increasingly utilised marine and coastal management tool, with rates of designation rising steeply over the last twenty years. MPAs are most commonly designated for biological conservation objectives and the management is thus focused primarily on meeting conservation goals, with associated monitoring programs gathering data on a narrow suite of biological indicators. However, MPAs also have a wide range of potential social and economic impacts and the ability to meet the goals of an MPA is highly influenced by the often unmonitored perceptions and buy-in of local stakeholders. Here we examine a range of stakeholder perceptions concerning a coastal MPA in South Australia. We conducted semi-structured interviews with individuals engaged in the MPAs planning and designation process, as well as those involved with its ongoing management. We explored their understanding of the purpose of the MPA, whether they thought the MPA was successful and the future management challenges the MPA might face. In particular, we focused on eliciting from stakeholders indicators they thought should be used to monitor the ongoing performance of the MPA. Perceptions varied between stakeholder groups, however, the majority of respondents highlighted the importance of socio-economic factors in the ongoing performance of the MPA. The vast majority of them suggested both biological and socio-economic indicators that should be incorporated into monitoring programs. Our findings highlight the need for MPA planning and management, when defining goals and developing monitoring programs, to be mindful to incorporate social and economic, as well as, biological indicators.

Dominate algeas and rare animals of Point Lookout Dive Sites, North Stradbroke Island, Queensland

Survey of algae species and rare animals listed by common species name, from various dive sites around Point Lookout. Species were surveyed at different segments from 0-20m, 25-45m and 50-70m.