How kelp farmers retrieve longlines, anchors and mooring gear at season's end without losing it — pull order, recovery technique and winterising decisions.
Every kelp farm owner eventually learns the same lesson: deploying gear is the easy half of the engineering problem, and taking it back is the half that costs you. The autumn pull — retrieving a season's worth of longlines, bridles, anchors and hardware from cold, building seas — is where farms lose equipment, bend winches and, occasionally, hurt people. Done well, it is a disciplined, almost boring sequence of lifts and winch pulls. Done casually, it is the week you feed the seabed a brand-new mooring grid. This guide walks through the pull as working farms actually run it: planning the order, recovering lines and anchors safely, deciding what stays down for winter, and preventing the slow bleed of lost gear.
When you deploy a mooring grid in spring, the gear is clean, the crew is fresh and you control the sequence. At the autumn pull, none of that holds. Lines that went down as tidy 100-metre catenaries now carry tonnes of wet kelp (if you are pulling before harvest), fouling growth, tangled cultch and sediment. Anchor lines have had a full season of cyclic loading and may be buried, chafed or hooked under rock ledges.
The physics also runs against you. A slack line lifts evenly; a fouled, tensioned line lifts in surges. The load on a recovery line is rarely the load you calculated — it is whatever the seabed decides to add. This is why retrieval deserves the same formal planning as mooring design: a load path for every component, and a plan for when the path refuses to behave.
The natural order is the reverse of deployment, with one adjustment: recover the highest-value, highest-risk items first while weather days are available. For most farms that means:
Autumn weather comes in pulses. A realistic pull plan assumes you get perhaps half the workable days you hope for. Pull estimates should be built from observed lift times on a trial line — time one full line recovery before you schedule forty. Crew fatigue compounds: the third consecutive day of hauling wet rope is slower and more dangerous than the first. Rotate the heavy stations, and treat the go/no-go decisions with the discipline described in weather threshold planning — retrieval in marginal conditions is how gear and fingers get lost.
The standard recovery is a controlled winch pull from one end:
If lines have been down through a storm season, expect sections to be chafed nearly through. Pull them gently enough that they fail at the winch — where you still recover both ends — rather than parting at depth and leaving an orphaned length on the bottom.
This is the real strategic decision of the autumn pull, and there is no universal answer.
Retrieving anchors each year lets you inspect the entire ground tackle, retire fatigued shackles and chain, and re-set a precise grid next spring. On farms with soft mud or sand bottoms, anchors usually break out cleanly, and annual retrieval is normal practice.
On exposed sites, or where anchors are embedded in hard substrate, pulling them is slow, brutal work with a real chance of parted legs. Many farms leave anchors and ground chain down, recovering only the risers and attaching a small, well-marked winter buoy (or, where regulations and traffic allow, recording positions and removing surface marks entirely). The riser legs — the sections that see the worst chafe — come home for inspection. If you go this route, log every position to GPS with backup soundings, and photograph the as-left state. "We know roughly where they are" is not a survey.
Whichever you choose, decide on the quay in the off-season plan, not on the water with weather coming in. The full checklist of what the quiet months then demand is covered in off-season maintenance.
Gear recovery is only half finished when the boat ties up. The same day, ideally:
Every farm loses a little gear. Well-run farms lose very little and know where it went.
Prevention is mostly marking and record keeping: surface buoys that survive UV and ice, lines weighted so slack can't drift into traffic, and a deployment log that records GPS positions at set, not at plan. When gear does go missing, report it per your lease conditions and local maritime rules — in many jurisdictions, unreported lost aquaculture gear is itself an offence, quite apart from the ghost-fishing and navigation hazards it creates.
For gear you can locate but not lift — an anchor snagged under a ledge, a wrapped chain — mark it, log it, and book a diver or a lifting vessel rather than applying ever-larger winch horses. A 40-tonne pull that finally frees the anchor can also free it straight through the water column at speed.
In most temperate regions the pull follows harvest in late spring or early summer, but farms that run year-round structural gear retrieve in early autumn before the first serious storm trains arrive. The governing rule: be finished before sustained autumn gales make small-boat work marginal, not in the middle of them.
Yes, and many exposed-site farms do. Leave down only robust ground tackle (anchors and chain), recover risers and lines for inspection, mark or log positions accurately, and comply with your lease conditions and local navigation-marking requirements.
Stop winching before anything parts. Change the pull angle by repositioning the boat; if it still refuses, buoy it, record the position and return with lifting tackle or a diver. Never shock-load a snagged line.
Well-managed farms lose a small fraction of hardware per season and can account for every item. If you cannot reconcile your deployment log at pull time, tighten marking and record keeping before scaling up.
Yes, and then some. Cold water shortening working windows, heavy gear under unpredictable load and end-of-season fatigue make the pull one of the year's higher-risk operations; run it under your full farm safety protocols with explicit go/no-go weather thresholds.
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