Assessment of the physical characteristics and fishing performance of gillnets using biodegradable resin (PBS/PBAT and PBSAT) to reduce ghost fishing

Abstract

1. Ghost fishing is caused by derelict synthetic-fibre nets that have been lost at sea. Thus, biodegradable nets have been developed with the aim of protecting marine ecosystems. 2. The performance of biodegradable nets and their ability to replace conventional gillnets was assessed. Two types of biodegradable nets were used in the experiment: one made from a blended resin containing 90 wt% polybutylene succinate (PBS) and 10 wt% polybutylene adipate-co-terephthalate (PBAT) (Bio-1), and the other made from a polybutylene succinate co-adipate-co-terephthalate (PBSAT) resin (Bio-2) with improved flexibility and physical homogeneity. 3. For No. 3 monofilaments (standard diameter, Ø, 0.284 mm), Bio-1 and Bio-2 both showed a wet straight-line breaking strength of around 99% that of polyamide (PA). For No. 2 monofilaments (Ø 0.200 mm), the wet straight-line breaking strengths of Bio-1 and Bio-2 were 84.9 and 93.0% that of PA, respectively, indicating worse physical properties for Bio-1 at No. 2 thickness. 4. The wet knotted breaking strengths of No. 3 thickness Bio-1 and Bio-2 were 92.9 and 82.7% that of PA, respectively. The straight-line breaking strength of Bio-2 was 1.1 times that of Bio-1. The wet knotted breaking strengths of Bio-1 and Bio-2 were 80.2 and 93.4% that of PA, respectively, and the knotted breaking strength of Bio-2 was around 1.2 times that of Bio-1. 5. Regarding flexibility, for No. 3 thickness monofilaments, the mean wet stiffness values of PA, Bio-1, and Bio-2 were 9.50, 15.23, and 9.68 g, respectively, indicating that Bio-2 was similar to PA and around 1.6 times softer than Bio-1. 6. The fishing performance, by weight, was PA > Bio-2 > Bio-1; however, the difference between PA and Bio-2 was not statistically significant. Biodegradable nets may not be a perfect solution, but we believe that they can contribute greatly to reducing ghost fishing and protecting marine ecosystems.

Anchor Forces on Coir-Based Artificial Seagrass Mats: Dependence on Wave Dynamics and Their Potential Use in Seagrass Restoration

“…Our results should thence provide a starting point for the design of natural mats reinforced with biodegradable materials ultimately having similar bulk mechanical properties as those shown in Table 2. Such materials could be polybutylene succinate (PBS) and polybutylene adipate-co-terephthalate (PBAT), which have been proven to have similar properties to PP and HDPE (Xu and Guo, 2010), or a combination of both (PBSAT), shown to be significantly similar to polyamide (PA) (Seonghun et al, 2020). These materials have been tested in the field to replace conventional fishing nets with biodegradable nets whose tensile strength is adequate for fishing while being a potential solution to ghost fishing (Grimaldo et al, 2018).…”

A thermoanalytical insight into the composition of biodegradable polymers and commercial products by EGA-MS and Py-GC-MS

“…However, there is a lack of knowledge on the potential for environmental impacts associated with biodegradable mulch films, coupled with concerns on the effectiveness of the current international standards [14], [18]. The most common synthetic polymers used in fishing gear are polyamides, which are very persistent in marine environment and once lost, these intact nets can result in ghost fishing, continuing to trap and kill marine life [19], [20]. To mitigate the impact of abandoned or lost fishing nets on marine ecosystems, biodegradable polymers are object of attention and tests for this specific application [19], [21], [22].…”

L’analyse de l’activité de démaillage : intérêts pour et dans la conception d’un filet de pêche biodégradable

“…Depuis quelques années, les recherches portant sur la conception d'engins de pêche biodégradable se multiplient. Ces travaux abordent la question des propriétés mécaniques de ces nouveaux engins (Seonghun, Pyungkwan, Seongjae, & Kyounghoon, 2020 ;Su, Moe Føre, & Grimaldo, 2019), de leur efficacité (Grimaldo, Herrmann, Su, Føre, Vollstad, Olsen, Larsen, & Tatone, 2019 ;Grimaldo, Herrmann, Jacques, Vollstad, & Su, 2020 ;Kim, Kim, Jeong, Bae, Lim, & Su, 2018) et de leur impact sur l'environnement (Wilcox, & Hardesty, 2016). Wilcox et Hardesty (2016) notent que l'usage d'un filet de pêche biodégradable est pertinent parce qu'il limite l'écotoxicité ; en revanche, il ne résout pas le problème de pêche fantôme.…”