Brown strap kelp (Ecklonia radiata), underwater in bright turquoise coastal New Zealand ocean, sunlight filtering from above, natural daylight. Full plant visible from holdfast to blade tips — robust central stipe (stalk) anchored to rock, branching into strap-like flattened fronds with ruffled or toothed margins, rich brown to golden-brown colouring, translucent where backlit by sunlight filtering from above. Rocky reef substrate below. Shallow depth of field, bright turquoise water background suggested. Strap frond texture and ruffled margin detail resolved. Plant occupies maximum 65% of frame. No props. No text.