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Article: Use of a smartphone application for self-reporting in small-scale fisheries: Lessons learned during a fishing closure in the western Baltic Sea

Meyer, Steffi / Krumme, Uwe / Stepputtis, Daniel / Zimmermann, Christopher

Ocean & coastal management. 2022 June 01, v. 224

2022

Abstract: There is a lack of data on the experience of the use of mobile devices in commercial small-scale fisheries but which are important to evaluate the suitability of these approaches for fisheries monitoring. In February and March 2018, the German Baltic ... ...

Abstract	There is a lack of data on the experience of the use of mobile devices in commercial small-scale fisheries but which are important to evaluate the suitability of these approaches for fisheries monitoring. In February and March 2018, the German Baltic small-scale fishery used a smartphone application for self-reporting of fishing activities to demonstrate compliance with the terms of a fishing closure of cod, which prohibited to fish deeper than 20 m. A total of 1618 trips and 7972 gear activities from 107 vessels were identified and categorized. Data review showed that not all data could be used directly due to operating or technical errors (e.g. mismatch in time and space of self-reported and actual gear activities and missing records on geographical positions). By editing during data evaluation, the proportion of useable trips and gear activities increased from 67 to 78% and from 29 to 69%, respectively. These data provided new insights into the activities of small-scale fishing vessels (<12 m), especially of the data-poor segment of vessels smaller than 8 m (e.g. for gillnets: mean net length of 664 m ± 538 SD, mean soak time of 30 h ± 12.9 SD, mean trip duration of 2.9 h ± 1.6 SD). Due to the high spatio-temporal resolution, the fishers could demonstrate compliance with the closure, with 99% of all recorded gear activities performed in areas shallower than 20 m. Based on the fast and short operation at sea observed, recording intervals of max. 1 min are advisable for small-scale vessels. Potential suggested improvements involve training of fishers, an independent GPS sensor, a remote control and tailored tools for data analysis to properly address future developments of smartphone applications for the use in data collection in small-scale fisheries.
Keywords	coastal zone management ; compliance ; data collection ; fisheries ; gillnets ; mobile telephones ; remote control ; Baltic Sea
Language	English
Dates of publication	2022-0601
Publishing place	Elsevier Ltd
Document type	Article
ISSN	0964-5691
DOI	10.1016/j.ocecoaman.2022.106186
Database	NAL-Catalogue (AGRICOLA)

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Book ; Online: SimuNet - Ein Werkzeug zur Fanggeräteoptimierung

Breddermann, Karsten / Lichtenstein, Uwe / Kosleck, Sascha / Stepputtis, Daniel

Abschlussbericht

2023

Abstract: Die Fischereipolitik der EU fordert und fördert durch den Europäischen Meeres- und Fischereifond (EMFF) Maßnahmen, die darauf abzielen die Fischerei wettbewerbsfähig, ökologisch nachhaltig, rentabel, ressourcenschonend, innovativ, wissensbasiert und ... ...

Abstract	Die Fischereipolitik der EU fordert und fördert durch den Europäischen Meeres- und Fischereifond (EMFF) Maßnahmen, die darauf abzielen die Fischerei wettbewerbsfähig, ökologisch nachhaltig, rentabel, ressourcenschonend, innovativ, wissensbasiert und sozial verantwortungsvoll zu gestalten. Im Hinblick auf die verwendeten Fischereigeräte bedeutet das: • Anpassung der Selektivität des Fanggeräts an die Erfordernisse, • Reduktion der Einwirkung des Fangeräts auf die Meeresumwelt (z.B. den Meeresboden), • Reduktion des Schleppwiderstands des Fanggeräts/-systems, um so den Treibstoffverbrauch und damit den CO2-Ausstoß zu senken. Die Neu- bzw. Weiterentwicklung von Fanggeräte ist hierfür eine Grundvoraussetzung. Eine wichtige Hilfestellung bei der Entwicklung ist die Simulation der Form des Fanggerätes und der damit verbundenen Hydrodynamik. Allerdings fehlt es zurzeit an Simulationswerkzeugen, die es erlauben die Hydrodynamik und Verformung des Systems gekoppelt zu analysieren. Daher soll in dem vorliegenden Projekt eine quelloffene (”open source“) Simulationssoftware entwickelt werden, welche die gekoppelte Simulation von Hydrodynamik und Verformung von Fanggeräten ermöglicht. Innerhalb des Projekts liegt der Fokus zwar auf geschleppten Fanggeräten (Schleppnetze), aber das zu entwickelnde Simulationswerkzeug ist auch für andere Fanggerätetypen (z.B. Reusen, Stellnetze, Waden, Netzkäfige) anwendbar. Im vorliegenden Bericht wird auf den gesamten Bearbeitungszeitraum vom 16.04.2020 bis zum 30.06.2023 eingegangen.
Keywords	Text ; ddc:630 ; ddc:600
Language	German
Publisher	Univ. Rostock; Thünen-Institut für Ostseefischerei
Publishing country	de
Document type	Book ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Hydrography on fishing vessels - a feasability study leads to an open source development

Hermann, Andreas / Stepputtis, Daniel / Furkert, Frederik / Björner, Mathis / Naumann, Michael

2023

Abstract: The knowledge of hydrographic conditions is of central importance for the assessment of the state of marine ecosystems ? with all its implications on climate or usage of the sea. Currently, data collection is mainly carried out by environmental ... ...

Abstract	The knowledge of hydrographic conditions is of central importance for the assessment of the state of marine ecosystems ? with all its implications on climate or usage of the sea. Currently, data collection is mainly carried out by environmental monitoring programs and very costly. Spatial and temporal resolution is insufficient and data validation is mostly hand-operated before it can be stored in scientific databases. Therefore, we urgently need new monitoring strategies. More efficient data collection not only contributes to a better understanding of the marine ecosystem, but is relevant to issues such as: ÷ Fish stock forecasts ÷ Monitoring of the marine environment e.g. North and Baltic Sea (HELCOM) ÷ State on ocean acidification, oxygen deficiency and eutrophication ÷ Implementation of sustainable development goals (e.g. MSRL in Europe) Ships of opportunity could play an important role here. Today, ferries and cargo ships can be equipped with FerryBox systems 1 to collect hydrographic data, but they are limited to surface water measurements and ferry routes or sea lanes. In contrast, fishing vessels deploy their gear deep below the surface. Here we present a method for using fishery as ships of opportunity in data collection and our results from a feasibility study on a fleet of commercial fishing vessels over the period of nine weeks. We show our experience with existing systems, the collected data, feedbacks from fishermen and a fine granulated list of necessary system features, which are not yet offered by existing systems. Therefore we started to develop HyFiVe (Hydrography on Fishing Vessels) - an autonomous measurement system to be installed on board of fishing vessels. We show that this can carry out a significant increase in the temporal and spatial data collection density at a relatively low cost. Further we present the development status, the results of which will be published under open source licenses.
Keywords	Text ; ddc:630
Subject code	551
Language	English
Publishing country	de
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The capability of square-meshes and fixed-shape meshes to control codend size selection

Bak-Jensen, Zita / Herrmann, Bent / Santos, Juan / Melli, Valentina / Stepputtis, Daniel / Feekings, Jordan P.

Fisheries Research. 2023 Aug., v. 264 p.106704-

2023

Abstract: Trawl codends are commonly made of diamond-mesh netting. However, diamond-mesh codends vary in mesh geometry along its length and during fishing due to catch build up. This introduces variability in the size selection process. This phenomenon compromises ...

Abstract	Trawl codends are commonly made of diamond-mesh netting. However, diamond-mesh codends vary in mesh geometry along its length and during fishing due to catch build up. This introduces variability in the size selection process. This phenomenon compromises the rationality of regulating exploitation patterns in trawl fisheries through adjustments in codend mesh size. One technical solution often applied to achieve more well-defined size selection is turning the codend netting 45 degrees (square-mesh). However, there is a lack of evidence that square-mesh codends result in more constant size selectivity. Therefore, we aimed at quantifying the variability in size selection in square-mesh codends. We tested the size selectivity of three codends; a standard square-mesh codend, and two rigid codends where mesh geometries were fixed in diamond shape with an opening angle of 60° and square shape, respectively. The two rigid codends were used to establish baselines with limited variability in size selection. The size selectivity of these codends was compared to results - previously obtained for a standard diamond-mesh codend. Using Atlantic cod (Gadus morhua) as a case study, we demonstrated that the standard square-mesh codend had significantly larger variability in size selection compared to the fixed diamond-mesh codend. Moreover, we found no evidence that the standard square-mesh codend had lower variability in size selection than a standard diamond-mesh codend with same mesh size. These results demonstrate that the use of standard square-mesh codends is not sufficient to reduce variability in codend size selection. Additionally, we demonstrate that the sizes of fish retained is strongly dependent on mesh shape and openness. We conclude that a profound re-thinking over codend designs is required in order to achieve better control of size selection in trawl fisheries.
Keywords	Gadus morhua ; case studies ; fish ; geometry ; research ; Codend size selectivity ; Fixed mesh openness ; Diamond-mesh ; Square-mesh ; Mesh opening angle
Language	English
Dates of publication	2023-08
Publishing place	Elsevier B.V.
Document type	Article ; Online
Note	Use and reproduction
ZDB-ID	406532-3
ISSN	0165-7836
ISSN	0165-7836
DOI	10.1016/j.fishres.2023.106704
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Use of a smartphone application for self-reporting in small-scale fisheries

Meyer, Steffi / Krumme, Uwe / Stepputtis, Daniel / Zimmermann, Christopher

Lessons learned during a fishing closure in the western Baltic Sea

2022

Abstract	There is a lack of data on the experience of the use of mobile devices in commercial small-scale fisheries but which are important to evaluate the suitability of these approaches for fisheries monitoring. In February and March 2018, the German Baltic small-scale fishery used a smartphone application for self-reporting of fishing activities to demonstrate compliance with the terms of a fishing closure of cod, which prohibited to fish deeper than 20 m. A total of 1618 trips and 7972 gear activities from 107 vessels were identified and categorized. Data review showed that not all data could be used directly due to operating or technical errors (e.g. mismatch in time and space of self-reported and actual gear activities and missing records on geographical positions). By editing during data evaluation, the proportion of useable trips and gear activities increased from 67 to 78% and from 29 to 69%, respectively. These data provided new insights into the activities of small-scale fishing vessels (<12 m), especially of the data-poor segment of vessels smaller than 8 m (e.g. for gillnets: mean net length of 664 m ± 538 SD, mean soak time of 30 h ± 12.9 SD, mean trip duration of 2.9 h ± 1.6 SD). Due to the high spatio-temporal resolution, the fishers could demonstrate compliance with the closure, with 99% of all recorded gear activities performed in areas shallower than 20 m. Based on the fast and short operation at sea observed, recording intervals of max. 1 min are advisable for small-scale vessels. Potential suggested improvements involve training of fishers, an independent GPS sensor, a remote control and tailored tools for data analysis to properly address future developments of smartphone applications for the use in data collection in small-scale fisheries.
Keywords	Text ; ddc:630 ; Electronic reporting -- Mobile phone -- Artisanal fisheries -- Self-reporting -- Digital fisheries monitoring
Subject code	333
Language	English
Publishing country	de
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article: Reducing cod bycatch in flatfish fisheries

Santos, Juan / Stepputtis, Daniel / Oesterwind, Daniel / Herrmann, Bent / Lichtenstein, Uwe / Hammerl, Constanze / Krumme, Uwe

Ocean & coastal management. 2022 Apr. 01, v. 220

2022

Abstract: Management measures to facilitate the recovery of fish stocks can lead to shifts in traditional fishing patterns and target species. In the Baltic Sea, drastic reductions in catch quota for cod (Gadus morhua) force mixed demersal trawl fisheries to avoid ...

Abstract	Management measures to facilitate the recovery of fish stocks can lead to shifts in traditional fishing patterns and target species. In the Baltic Sea, drastic reductions in catch quota for cod (Gadus morhua) force mixed demersal trawl fisheries to avoid cod bycatch and focus on flatfish species. This study developed and tested a simple selection concept that aims to avoid cod bycatch in flatfish-directed trawl fisheries by removing a section of the top panel from the extension piece of the trawl (roofless concept). Sea trials testing the performance of a baseline roofless design, and two designs intended to enhance escape reactions of cod were conducted during two sea cruises. Analysis of the resulting catch data revealed that applying the baseline roofless design consistently reduced cod bycatch by ∼75%. Catches of the target species plaice (Pleuronectes platessa) and flounder (Platichthys flesus) were reduced by less than 15%; however, we estimated that catch losses of the two flatfish species could be balanced by increasing fishing effort to ∼8% and ∼12%, respectively. None of the two roofless designs, intended to enhance escape reactions on cod, improved the performance of the baseline design. Under the scenario of fishery choke caused by limited cod quotas, we estimated that the use of the baseline roofless concept could increase fishing possibilities for flatfish by more than 300%.
Keywords	Gadus morhua ; Platichthys flesus ; Pleuronectes platessa ; bycatch ; coastal zone management ; flounder ; Baltic Sea
Language	English
Dates of publication	2022-0401
Publishing place	Elsevier Ltd
Document type	Article
ISSN	0964-5691
DOI	10.1016/j.ocecoaman.2022.106058
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: iFO (infrared Fish Observation) - An open source low-cost infrared underwater video system.

Hermann, Andreas / Chladek, Jérôme / Stepputtis, Daniel

HardwareX

2020 Volume 8, Page(s) e00149

Abstract: Underwater video surveillance is an important data source in marine science, e.g. for behaviour studies. Scientists commonly use water resistant ruggedized monitoring equipment, which is cost-intensive and usually limited to visible light. This has two ... ...

Abstract	Underwater video surveillance is an important data source in marine science, e.g. for behaviour studies. Scientists commonly use water resistant ruggedized monitoring equipment, which is cost-intensive and usually limited to visible light. This has two disadvantages: the observation is limited to space and time where visible light is available or, under artificial illumination, behaviour of marine life is potentially biased. Infrared (IR) video surveillance have been used before to overcome these. It records videos at visible light and under IR-illumination. With today's efficiency of IR-LED and video technology even low-cost systems reach visibility ranges suited for many application scenarios. We describe a low-cost open-source based hardware/software system (iFO). It consists of a single-board computer controlling the camera and lamps (with high power IR-LEDs), printed circuit boards (PCB), the underwater housings and 3D-printable models to mount PCBs in the housings and the housings to standard GoPro mounts. The Linux based software includes webserver, remote control, motion detection, scheduler, video transfer, storage at external hard disk and more. A ready-to-use SD-card image is included. We use rugged underwater housings with 100 m (optional 400 m) depth ratings. Finally, we describe a typical application observing the behaviour of cod in fish pots.
Language	English
Publishing date	2020-10-08
Publishing country	England
Document type	Journal Article
ISSN	2468-0672
ISSN (online)	2468-0672
DOI	10.1016/j.ohx.2020.e00149
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Book ; Online ; Thesis: Fishing gear technology to mitigate harbour porpoise and seabird bycatch in the Baltic Sea: Gillnet modifications and alternative fishing gear fish pot

Chladek, Jérôme Christophe [Verfasser] / Möllmann, Christian [Akademischer Betreuer] / Stepputtis, Daniel [Akademischer Betreuer]

2022

Author's details	Jérôme Christophe Chladek ; Christian Möllmann, Daniel Stepputtis
Keywords	Tiere (Zoologie) ; Animals (Zoology)
Subject code	sg590
Language	English
Publisher	Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky
Publishing place	Hamburg
Document type	Book ; Online ; Thesis
Database	Digital theses on the web

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Article ; Online: The capability of square-meshes and fixed-shape meshes to control codend size selection

Bak-Jensen, Zita / Herrmann, Bent / Santos, Juan / Melli, Valentina / Stepputtis, Daniel / Feekings, Jordan P.

2023

Abstract	Trawl codends are commonly made of diamond-mesh netting. However, diamond-mesh codends vary in mesh geometry along its length and during fishing due to catch build up. This introduces variability in the size selection process. This phenomenon compromises the rationality of regulating exploitation patterns in trawl fisheries through adjustments in codend mesh size. One technical solution often applied to achieve more well-defined size selection is turning the codend netting 45 degrees (square-mesh). However, there is a lack of evidence that square-mesh codends result in more constant size selectivity. Therefore, we aimed at quantifying the variability in size selection in square-mesh codends. We tested the size selectivity of three codends; a standard square-mesh codend, and two rigid codends where mesh geometries were fixed in diamond shape with an opening angle of 60° and square shape, respectively. The two rigid codends were used to establish baselines with limited variability in size selection. The size selectivity of these codends was compared to results - previously obtained for a standard diamond-mesh codend. Using Atlantic cod (Gadus morhua) as a case study, we demonstrated that the standard square-mesh codend had significantly larger variability in size selection compared to the fixed diamond-mesh codend. Moreover, we found no evidence that the standard square-mesh codend had lower variability in size selection than a standard diamond-mesh codend with same mesh size. These results demonstrate that the use of standard square-mesh codends is not sufficient to reduce variability in codend size selection. Additionally, we demonstrate that the sizes of fish retained is strongly dependent on mesh shape and openness. We conclude that a profound re-thinking over codend designs is required in order to achieve better control of size selection in trawl fisheries.
Keywords	Text ; ddc:630 ; Codend size selectivity ; Diamond-mesh ; Fixed mesh openness ; Mesh opening angle ; Square-mesh
Subject code	519 ; 600
Language	English
Publishing country	de
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Book ; Online: Technical approaches to avoid cod catches in Baltic Sea trawl fisheries

Stepputtis, Daniel / Santos, Juan / Zimmermann, Christopher

A report for the BALTFISH high level group

2020

Abstract: In the last few years, the Thünen Institute of Baltic Sea Fisheries developed and tested several selectivity devices for demersal trawls with the aim to reduce the unwanted bycatch of Baltic cod, while maintaining the high catchability of flatfish. This ... ...

Abstract	In the last few years, the Thünen Institute of Baltic Sea Fisheries developed and tested several selectivity devices for demersal trawls with the aim to reduce the unwanted bycatch of Baltic cod, while maintaining the high catchability of flatfish. This research is a direct response to the poorstatus of both Baltic cod stocks(ICES, 2019a, 2019b), resulting in reduced catch opportunities (Western Baltic cod) or a closure of the directed fishery (Eastern Baltic cod), respectively.to ad-hoc measures to alleviate a serious threat to the conservation of eastern Baltic cod, im-plemented by the European Commission by July 22, 2019(EU 2019/1248). The presented workup dates and complements the ICES report on ‘Technical strategies to avoid catches in the Baltic Sea trawl fisheries’ (ICES, 2019c). There is now (April 2020) much knowledge gained compared to the state of play in the ICES report. This can now be considered state-of-the-art technology. Since September 2019, two different approaches and a combination of the two were investigated: 1. modifications of the extensions and 2. modifications of the codend. For approach 1., the following selectivity devices were (further) developed and tested(Figure 1): (1)CODEX (COD EXcluder): A guiding panel in the extension of a trawl guides cod towards an escape opening. (2)ROOFLESS (in various configurations): The top panel of the trawl extension was removed to build a large escape opening (175cm, or330cm long). Additionally, configurations with stimulation ropes (STIPED) were tested. Both devices were mounted in a standardized 4-panel extension of the trawl, developed at the Thünen Institute (NEMOS, NEt Enabling MOdular Selectivity, Figure 3) to ensure a firm shape of the extension and hence reduce variability in the efficiency of the selection process. The experimental work was conducted during four cruises between September 2019 and February 2020. For CODEX, it was shown that cod catches could be reduced significantly, but also flatfish catches were reduced largely. The ...
Keywords	Text ; ddc:570
Subject code	333
Language	English
Publisher	Thünen-Institute of Baltic Sea Fisheries
Publishing country	de
Document type	Book ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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