Hello Danny
A nice presentation and thanks.
Ice ice is a Pandora's Box of multiple organisms affecting euchuematoid health.

Are Eucheuma and Kappaphycus equally susceptible -- under the same detrimental environmental conditions/stresses?

How does one go about selecting "resistant" strains from any one given strain or species?
What would be the selective pressures and how could you test for them?

Thinking about the present pandemic and "cures"...do you see any form of "vaccine" becoming available for the eucheumatoids to provide pest protection?

Thank you Alan

To answer your questions:

It seems K. alvarezii (and K. striatum?) is more susceptible to ice-ice than E. denticulatum under the same detrimental environmental stress based on personal observations. I think it has something to do with some inherent mechanism among eucheumatoids of producing antimicrobial compounds which could vary amongst species, like E. denticulatum being able to produce hydrogen peroxide and halogens as detected by the team of Marianne Pedersen. Also Matt Dring has a review paper entitled "Stress Resistance and Disease Resistance in Seaweeds: The Role of Reactive Oxygen Metabolism (Advances in Botanical Research, Vol,. 43, pp. 175-207 (2005) that will be a good reference.

I don't really have an answer on how we can select "resistant" strains unless we start from scratch of from using cultivars developed from spores or gametes where their genes still have the robustness against stressors.

High temperature and light intensity which are directly associated with global warming should be top on the list of selective pressures that can be used to test new strains developed from either spores or gametes. Salinity can be second in the list for the reason that most seaweed farms are coastal and shallow and are directly under the influence of freshwater sources and heavy downpour during tropical monsoon rains.

The pandemic gives us a hint on what can also happen to our seaweeds under this cloud of climate change. It seems that applying biostimulants that could promote better growth and health (affording the seaweed resistance to ice-ice and epiphytes) are working like "vaccines" for the current strains but for how long this will afford them such protection, I think, will need more studies. BFAR is now comparing the different biostims (including AMPEP and locally-produced versions) with some promising results.

I hope I have answered some of your questions?

Cheers, Alan.

Hi Dr Danny,

This is further to Dr Alan's suggestion, I would like to suggest farming of Sargassum as inter crop with Eucheumatoid cultivation as Sargassum has been reported to even repel grazers due to phlorotannins.

CRK Reddy

Hallo Danny

I have an idea to cultivate seaweed from 2 different species: Kappaphycus alvarezii and K. spinosum on the same rope alternately.

I think that when both species of seaweed are stressed due to the extreme changing environment then there are chemical compounds that are released to protect them. I found that spinosum has advantages or has better endurance than alvarezii so there is a chance that spinosum's chemical compounds can help reduce stress on alvarezii. How do you think about my opinion?

Hi Leila,

I used K. alvarezii in my experiment in Tosa Bay (Kochi, Japan) some years ago. There this tropical seaweed cannot tolerate temperatures below its normal range of 23-30oC like here in the Philippines. Temperature could fall below this range in autumn in the subtemperate latitude and the seaweed could manifest the ice-ice condition soon enough (a week or so), not a month long as you have sometimes observed in Brazil. Would it be that the decline in temperature in (Sao Paolo?) Brazil not that abrupt like those in Kochi? I think that suboptimal level of certain factors like temp, salinity, and light intensity may not immediately lead to ice-ice condition, but drastic change could immediately manifest the disease.

Best regards,
Danny

Hallo Danny,

Indonesia has also entered the age of 50 years in the development of seaweed cultivation. Until these days, there are still many problems faced here in Indonesia ranging from aspects of cultivation, spatial planning, marketing to post-harvest. Based on the above-mentioned problems, is there any suggestion from you that the above issues can be resolved

We actually share the same problems here in the Philippines and there is no easy solution to all these complex problems. But I think, we can approach these problems according to different stages, from: 1) pre-farming stage (i.e. access to good-quality seedlings of the right species, access by farmers to credit facilities), 2) farming stage (knowledge on seaweed health management, farming systems, impact of warming seas/global warming, pollution, peace & order), 3) post-harvest (including seaweed quality based on moisture content, carrageenan yield, gel strength, presence of contaminants, e.g. heavy metals), 4) marketing (farmgate price not reflecting the actual market price with middlemen/traders earning more than farmers), 5) processing (strong lobby by interest groups against carrageenan in the world market).