DOI: 10.5061/dryad.tx95x6b67
title: Underwater video of lake whitefish Coregonus clupeaformis spawning in lake Michigan

description: The lake whitefish Coregonus clupeaformis, dikameg in Anishinaabemowin,
 holds cultural importance, and is a mainstay of commercial, recreational,
 and subsistence fisheries throughout North America. In the Laurentian
 Great Lakes, declines in recruitment, since the early 2000s, have raised
 concerns among stewards and fishery managers. A more detailed
 understanding of the lake whitefish mating system could help resolve
 potential recruitment bottlenecks and thus inform appropriate stewardship
 actions. Herein, we describe, for the first time, a single lake whitefish
 spawning event captured using high-resolution underwater videography. From
 94 h spent on the water, we captured and analyze a 4.5 min video clip that
 shows pre-mating, mating, and post-mating behaviour of a male and female
 lake whitefish from Lake Michigan. The clip shows a number of what we
 interpret as courtship, site-selection, and spawning behaviours
 culminating in release of about 20 eggs in a single spawning event.
 Behaviours that included travelling, physical contact, chasing, circling,
 orienting, and gamete release are described and time-referenced to a video
 supplement. This single observation is part of a larger project to assess
 lake whitefish spawning behaviour in the wild but is noteworthy in that it
 provides new insights into the spawning behaivour of lake whitefish and
 appears consistent with reproductive behaviours observed in European
 coregonines.
description: During 2022-2023, we used a Boxfish Robotics
 (https://www.boxfishrobotics.com) “Luna” craft to capture high-resolution
 underwater footage of spawning lake whitefish in lakes Huron and Michigan.
 The Luna craft is a next-generation drone that utilizes advanced
 full-frame imaging from a 4K 10-bit 4:2:2 120p Sony A7SIII camera equipped
 with either a Sony 16-35 mm f/2.8 or a Sony 24mm f/1.4 Zeiss lens. In
 shallow water, a 250-mm Nauticam glass dome port was used for the best
 edge-to-edge image quality, but for deepwater filming, a 200-mm Boxfish
 acrylic dome rated for 500 m depth was used. High sensitivity up to ISO
 409,600 provided exceptional low-light camera performance. Two dimmable
 8,500-lumen lights attached via adjustable arm mounts to the front of the
 craft provided ample illumination under all light conditions encountered.
 The ROV was tethered to the surface by a 300-m long, 2.7-mm diameter,
 lightweight, fiber-optic cable which allows recording on the surface in 4k
 ProRes Raw at 30p and frame stabilizing in post-production. The craft was
 controlled from the surface via a pilot console equipped with a 17-inch 4K
 monitor and a 10-inch sunlight readable secondary navigation display. The
 ROV carried sensors for depth, acceleration, internal humidity,
 temperature, and pressure and a 3D compass and precision gyroscope. A
 Subsea USBL transmitter and receiver provided GPS location of the ROV
 underwater (i.e., georeferenced on a map) and a Doppler Velocity Log
 sensor allowed the pilot to hold station thereby facilitating precise
 real-time control and adjustment of the craft and camera.
description: # Lake Whitefish *Coregonus clupeaformis* Spawning
 [https://doi.org/10.5061/dryad.tx95x6b67](https://doi.org/10.5061/dryad.tx95x6b67) The dataset is a 4.5-minute .mp4 underwater video segment showing a lake whitefish *Coregonus clupeaformis* spawning event captured in Little Traverse Bay, Lake Michigan (45.392274 N, 84.923740 W) that began at 19:59, 3 h after sunset (17:02), on 24 November 2022. The video clip commences with what we interpreted as courtship behaviour between a single female and a single male culminating in recovery after a single gamete release. The ripe female was readily identifiable by a characteristic distended abdomen. The video was captured using a Boxfish Robotics ([https://www.boxfishrobotics.com](https://www.boxfishrobotics.com)) “Luna” craft, which is a next-generation drone that utilizes advanced full-frame imaging from a 4K 10-bit 4:2:2 120p Sony A7SIII camera equipped with either a Sony 16-35 mm f/2.8 or a Sony 24mm f/1.4 Zeiss lens with a 250-mm Nauticam glass dome port. Two dimmable 8,500-lumen lights attached via adjustable arm mounts to the front of the craft provided ample illumination under all light conditions encountered. The ROV was tethered to the surface by a 300-m long, 2.7-mm diameter, lightweight, fiber-optic cable which allowed recording on the surface in 4k ProRes Raw at 30p and frame stabilizing in post-production. The craft was controlled from the surface via a pilot console equipped with a 17-inch 4K monitor and a 10-inch sunlight readable secondary navigation display. ## Description of the data and file structure The data file is 791 Mb; 3840x2160 (frame width x height); .mp4 format which provides the raw material upon which our analysis of lake whitefish spawning behaivour was undertaken.