היומן של shaun-lee

10:30 am 8 Jan 2022
High tide 12:45
-36° 45' 018” S , 174° 59' 015” E
Depth 20m
Substrate recorded as high current mud
Site chosen for investigation as a dominant habitat in marine reserve proposal
Bottom time 25mins (100bar air)

Vis 4-5m at surface, 1-2m on the bottom
Mud was very soft (for 8cm then harder below)
Investigated a 20m x 20m area
Mediterranean fanworm (1-2 per sq m)
Many sponges and clubbed tunicates
I put my hand in seven times and pulled up:

• Five very large (historic) green-lipped mussels, one had a top and bottom shell which I have not seen before but it broke
• Two scallop shells in ok condition, not particularly big, also saw a scallop on the surface

Straight away, lots of shell under the surface, very easy to find.
Massive school of blue mackerel or juvenile kahawai circled me as I ascended at 15m

20m North East of Passage Rock
10 Jan, 2022, 12:30pm
High Tide 1:40 pm

Red-billed gulls breeding and Reef heron fishing on Passage Rock.

75m transect
35minutes
Current low
Vis 2m
Depth 5m
Substrate: Rocks and sand => Gravel => Mud
Epibenthic fauna dominated by Mediterranean fanworm and pleated tunicate barring a nice patch of White-striped anemone.
Mud was soft and deep, I put my hand in seven times. Green lipped mussel shell four times at 25cm, scallop twice at 10-15cm, one plunge found no shell.

Nice to find a fisher parked by my boat when I surfaced to check I wasn't fishing in the marine reserve :D

Just inside the bay
10 Jan, 2022, 10am
High Tide 1:40 pm

Circled around a bit
15minutes
Current low
Vis 2m surface, 1m bottom. It was not good enough to use my fancy camera or spend much time.
Depth 5m
Substrate: Soft mud, heaps of crab/shrimp holes
I put my hand in the mud seven times. Shell at 10cm deep every time. Four large clam shells, 2 scallop shells and one predatory snail. Some smaller shell.

South side of Maria Island
11:40am
High tide 11:30am
Depth 8m
Vis 5m, very windy recently

I have been hearing about how awesome rhodolith beds are for years but never seen one. I know they are an important and habitat with nursery / recruitment benefits and has been in decline for decades in the Hauraki Gulf. I find a lot of individual rhodoliths but never more than five in a square meter. It was very exciting to bump into this bed at the Noises. I did not measure it but it was bigger than 10x4m. I imagine it is protected from dredges by the adjacent rocky reef.

I was blown away by the complexity of it, the bed dramatically increases the complexity and surface area of the seafloor. The bed was associated with other dead shell and gravel. I took a lot of photos of it and was pleased to see juvenile tipa / scallops in the bed along with a lot of other life. I was worried about the algae / biofilm smothering the photosynthesising ability of the rhodoliths but they might be quite resilient to seasonal growths.