Title:

Multiple - Before After Control Impact (M-BACI) analysis of the effect of a 3D marine seismic survey on Danish Seine catch rates

Project Number:

2019-072

Organisation:

Fishwell Consulting Pty Ltd

Principal Investigator:

Ian Knuckey

Project Status:

Current

FRDC Expenditure:

$647,850.00

Program(s):

Environment, Industry

Need

Apart from the general concern regarding impacts of seismic on commercial fishing, there is specific concern from fishers operating in Bass Strait that, as one of the larger 3D surveys in the region, the CGG MSS will: 1) interrupt their fishing activities as they will not be able to work in active zones while the MSS is taking place; and, 2) negatively impact on the fishing catch rates both during and after the MSS. There is a lot of anecdotal information from fishers about the impact of MSS on fishing but very little quantitative data to support claims of adverse impacts. With CGG support, a Multiple Before After Control-Impact (M-BACI) survey was designed by Fishwell Consulting to address the second issue, particularly the level of impact on Catch per Unit Effort (CPUE) of key species to the Danish Seine fleet in the area, namely Eastern School Whiting (Silago flindersii) and Tiger Flathead (Neoplatycephalus richardsonii). It is intended to apply this survey design during the upcoming CGG MSS due to commence in January 2020. CGG has agreed to fund $300,000 towards an M-BACI survey of Danish Seine catch rates. This proposal is submitted to FRDC to seek additional funding to conduct a survey over at least two periods: Period 1 survey during or immediately after the MSS, and depending on the results from the initial survey, Period 2 survey, 2-4 months following the MSS. The results will be of value not just in Bass Strait but could have significant ramifications around Australia in areas where oil and gas fields exist around productive fishing grounds.

Objectives

1. Examine effect of seismic testing on Danish seine catch rates of Tiger Flathead

2. Examine effect of seismic testing on Danish seine catch rates of Eastern School Whiting

3. Consider the results of the survey with respect to future marine seismic exploration impact on fisheries

Phase 1 Summary for FRDC project 2019-072: Multiple - Before After Control Impact (M-BACI) analysis of the effect of a 3D marine seismic survey on Danish Seine catch rates

Report
ISBN:
ISSN:
Author(s):Ian Knuckey
Date Published:July 2020
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The project is a four phase research program being conducted in the Danish seine commercial fishery off Lakes Entrance that looks to: 
 
1. Examine effect of seismic testing on Danish seine catch rates of Tiger Flathead
2. Examine effect of seismic testing on Danish seine catch rates of Eastern School Whiting
3. Consider the results of the survey with respect to future marine seismic exploration impact on fisheries
 
The results from Phase 1 have now been reviewed and this summary document details the findings. Subsequent phases of research will be released upon completion and review. 
 
It is important to note that the phase 1 results indicate a negative impact on both Whiting and Flathead catches in the Danish Seine Fishery. This however, is only the first phase of the research program so should be read as one data set on its own and no long term conclusions drawn from these results. 

M-BACI Phase 1-2-3 Summary

Report
ISBN:
ISSN:
Author(s):Ian Knuckey
Date Published:October 2020
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This summary report covers catch rates following phase 1 - 3 of the project of key target species - flathead and whiting. 
Multiple Before–After, Control–Impact (M-BACI) experimental designs allow for robust tests of environmental impacts in real world situations. M-BACI designs involve environmental measurements taken from multiple Impact Sites (subjected to the disturbance and potentially affected by it) and multiple Control Sites, which are similar to the impact sites but not subject to the disturbance. Each site is then sampled multiple times before and after the disturbance event to ensure appropriate temporal replication. M-BACI designs are a robust impact assessment tool because (i) they account for natural spatial and temporal variation, (ii) they provide strong evidence that the disturbance event as the cause of impact, and (iii) they allow for the estimation of the magnitude of environmental change caused by the disturbance.
This summary report covers catch rates following phase 1 - 3 of the project. 
Commercial catches of whiting (from logbook data) exhibited substantial year-to-year variation
• During Phase I, the impact effect on whiting was estimated to be a 99.7% reduction in catch rates relative to Control Sites This is statistically significant.
• During Phase II, the impact effect on whiting was estimated to be a 42.7% reduction in catch rates relative to Control Sites. This is statistically significant.
• During Phase III, the impact effect on whiting was between 79.5% less and 60.1% more than those from Control Sites. This is not statistically significant.
Overall, the M-BACI analyses provide robust evidence for a negative impact of seismic acquisition on whiting catch rates in the Danish Seine Fishery up to ~100 days following the MSS.
In general, commercial flathead catches (from logbook data) declined over 2015 to 2019 (Figure 8). The decline continued during 2020.
• During Phase I, the impact effect on flathead was estimated to be a 78.1% reduction in catch rates relative to Control Sites. This was statistically significant.
• During Phase II, the impact effect on flathead was estimated to be a 58.0% reduction in catch rates relative to Control Sites. This was statistically significant.
• During Phase III, the impact effect on flathead was estimated to be a 65.5% reduction in catch rates relative to Control Sites. This remained statistically significant.
Overall, the M-BACI analyses provide robust evidence for a negative impact of the seismic acquisition on flathead catch rates in the Danish Seine Fishery up to ~200 days following the MSS.