Kelp Talk

Curious about kelp

  • WillowSkye by WillowSkye

    What effect does ocean temperature have on the growth of kelp? Would certain species of kelp perhaps grow faster in an ocean temperature equal and above to 27 degrees Celsius (hurricane season) and if so, could sudden exponential growth in kelp be used as an indication of the advent of a hurricane in that particular area - almost like early warning?? Also, can one expect to see more kelp during the Summer Solstice (ex. 2 weeks before 21 June and 2 weeks after) as one assumes photosynthesis would be at its peak? Thanks


  • jebyrnes by jebyrnes scientist

    It's a tricky area, and one we are very curious about. Kelps typically require cool nutrient rich waters. While their growth can accelerate in slightly warmer water due to metabolic increases, often past a threshold they begin to have problems and/or nutrient levels drop so low as to deter growth. Many kelps store nutrients, and this is not as big of a problem for some as Macrocystis (which has very little storage capacity). But even for those that do store, their microscopic gametophytes - sort of like a seed bank - are often negatively effected by warming waters. Whether there is a general effect of temperature change on the same phase of kelp life history or not is an open question, and one that some of the members of our science team are trying to tackle. There's some great work by folk like Thomas Wernberg on this for some species.

    With respect to peaks, often the summer is a time of peak biomass due to increased light and warmer temperatures. Some areas, such as California, get big boosts of nutrients in the spring which kelps then use into the summer. Peak biomass can vary - often it's in the mid to late summer for many, but not all, species, as afterwards storms and other events can lead to big decreases in standing crop. There's wonderful work by people like Dan Reed, Inka Bartsch, Matt Edwards, Alejandro Buschman Rubio, Guri Song Anderson, Brenda Konar, and others on this for a variety of different species of kelp in a variety of different locales.


  • WillowSkye by WillowSkye in response to jebyrnes's comment.

    Thanks very much for excellent explanation - very interesting subject matter. From your explanation, I gather that Kelp is very sensitive to the temperature of the water. I wonder what effect Global Warming will have on Kelp in the long run? The names of the people you have listed - do you perhaps have some hyperlinks to their scientific papers - is it available to the public? Just for interests sake, I drink Norwegian Kelp (says so on the bottle, but whether it really is Norwegian is a mystery) as a natural remedy for a thyroid problem as the latter is border case underactive. Been drinking it for 10 years now and my thyroid is normal. Doctors just smile when I tell them its the Kelp:)


  • Arass by Arass scientist

    Hi Willow,
    I like the way you are thinking. You are absolutely correct that one of the cool things about this project is the information that it can provide not only about kelp, but also about other factors that are even harder to measure. For example Kyle, I and others have done some work looking at changes in kelp canopy cover as a measure of local wave disturbance (; unfortunately not open access but you can message me for a pdf if interested). It happens that warm water temperature is actually pretty easy to measure directly, so is probably not worth inferring from kelp cover. a network of buoys is reporting temperature from points around the world in near real time (check it out here As to the effects of climate change on kelp, it is an important and very much open question.