2020-07-07 P&E Agenda - Item 3 - Attachment 1 - TNC Project Management Plan

During sampling, divers collected all bivalve shellfish within the quadrat area. If the shellfish were on hard
substrate, divers collected 10 cm into the substrate. All shellfish are placed into mesh collection bags and are
carefully checked. The mesh collection bags are attached to the shotline and pulled to the surface for
measurement on the research vessel or nearby shoreline.
Using calipers, shellfish are measured for height (the distance from the hinge axis to the distal margin of the shell),
length (the distance from left and right distal margins) and width (thickness of both valves) to the nearest
millimetre (see Figure 1). Oysters are returned to the restoration substrate after sampling. Oyster density is
calculated by Equation 1. Twenty adult oysters (≥2 years old) per transect are shucked and visually assessed for
gravid condition for each survey.




                                   Figure 1: Measurement guide for bivalve shellfish

Key Performance Indicators

i4 Survival of shellfish – The percentage of live shellfish per m2. If survival is ≥ the number of dead shellfish then
the population is stable or growing

                               Equation 1: 𝑠ℎ𝑒𝑙𝑙𝑓𝑖𝑠ℎ. 𝑚2 = (𝑠ℎ𝑒𝑙𝑙𝑓𝑖𝑠ℎ 𝑝𝑒𝑟. 0.25𝑚2 ) ∗ 4
                               Equation 2: 𝑆ℎ𝑒𝑙𝑙𝑓𝑖𝑠ℎ𝑖 = 𝑚𝑒𝑎𝑛 𝑠ℎ𝑒𝑙𝑙𝑓𝑖𝑠ℎ 𝑝𝑒𝑟 𝑚2 ∗ 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑟𝑒𝑒𝑓(𝑚2 )
                                                                     𝐿𝑖𝑣𝑒 𝑠ℎ𝑒𝑙𝑙𝑓𝑖𝑠ℎ.𝑚2
                               Equation 3. 𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑠𝑢𝑟𝑣𝑖𝑣𝑎𝑙 = (                            ) ∗ 100
                                                                  𝐿𝑖𝑣𝑒+𝑑𝑒𝑎𝑑 𝑠ℎ𝑒𝑙𝑙𝑓𝑖𝑠ℎ.𝑚2


i5. Physical conditions within tolerance ranges for target shellfish

i6. Number of recruits increased from baseline – Count of recruits per m2. Recruits are either counted in situ or
defined as oyster <10mm. If recruitment is greater than the number of dead shellfish, then the population is
being maintained by natural recruitment.

i7. Total shellfish deployed

i8 Density of live shellfish – the number of live shellfish, including recruits, per m2. The mean density (Equation
1) of live oysters provides a measure when compared to the benchmark of 50 shellfish per m2 that defines a
viable population density similar to that found on natural oyster reefs (Gillies et al. 2017).




78 | Bring Back the Fish MER plan 2020 – 2022