Query author’s posts & posts that have author’s id as meta value

Instead of a new WP_Query, use the pre_get_posts filter

add_filter('pre_get_posts', 'custom_query');
function custom_query($query) {
    if($query->is_main_query() && $query->is_author() && $_GET['eco']=='somemetakey') {
        $query->set('meta_query', array(
            array(
                'key' => 'somemetakey',
                'value' => $query->get('author')
            )
        ));
    }
}